Lets just get a few things straight upfront, before we get started, shall we?

• In terms of speed, the new Macbooks and Macbook Pros demolish the old G4's, even the top-of-the-line Powerbooks.
  
• The price, even on the old G4 laptops is considerably higher than similar era Windows laptops.
  
• The G4's you are going to find now are at least 3 years old, and in a lot of cases older than that.
  

Sounds bad, right? But consider this:

• Even though the G4's get spanked by the new Intel laptops in terms of speed, the G4's are still fairly spry at most common tasks.
  
• Your Powerbook is likely to at least hold SOME value when it comes time for you to sell it (perish the thought, though!)
  
• Though the computers are starting to age, most people take care of things they paid a lot of money for. Therefore, a lot of great condition laptops are still available.
  
• Dude, it's a sweet laptop!
  

Enough about all that. I am here to write a bit about the G4 Apple laptops. In this capacity I am a bit opinionated, but I have good reasons behind my opinions and hope that I will be able to help you decide whether a G4 era laptop is a good choice for you or not.

First, I would have to say that you ought to pass on buying any iBook unless you are really hard up for cash. Even the top of the line iBooks were little cousins to the monster Powerbook, and though at the time it might have made sense to pick one up (and save yourself $750 or so in the process over a PB,) now the gap in prices is not so great and it makes little sense to buy one now. Consider the following if you think I am being too hard on the iBook:

The bus speed is too slow, most being only 133 MHZ

The hard drive is too slow at 4200 RPM's

Even the last generation topped out at 1.42 GHZ.

Resolution tops out at 1024X768

At best you get 32 MB video RAM

The only audio in is the built in microphone

So, in short, if your love affair with the G4 processor is enticing you to buy an older Mac you are going to get more bang for the buck from the Powerbook line than the iBook line. If the only thing you can afford is an iBook I would (gasp) consider buying a used Dell. For the same amount of money you will probably get a better machine. Remember, computers are meant to be used. You aren't buying an "object de art" that is supposed to sit on a shelf looking cute (otherwise the iBook would smack that Dell like a red-headed stepchild.)

Secondly, there are probably only a few different Powerbooks I would consider buying as well (unless my needs were very basic.) This, again, falls under that rule that a laptop, even an attractive Apple Powerbook, must fulfill the purpose it was designed for: computing.

Third, pay extra attention to the condition of the Powerbook case. One thing the iBook had going for it was the white case, which while not being as cool looking as the aluminum casing on the Powerbook it also doesn't show scratches as bad. The Powerbook case is notorious for scratches and dents and takes them like a car door. The hinges are also a weak spot, so if in doubt ask questions about whether the screen will stay open at any angle.

Fourth, budget some money to max out the RAM on whatever machine you choose to get. The Powerbook will run Leopard just fine, as well as iLife (a hybrid of 07/08/09 works best..iweb 09, iphoto 09, iMovie 07, Garageband 08, iDVD 09) but programs like Photoshop Elements are RAM gobblers. I just maxed out my Powerbook for $100 by replacing the 2X512 modules with 2X1GB. You can also replace the hard drive with a larger model, but it is notoriously difficult surgery to perform and I wouldn't recommend it unless you are pretty handy.

If you are a maven for the old G4's and plan to have a usable laptop I would say (hold your rotten tomatoes, please) that you should really only consider 7 different models: A1139, A1138, A1107, A1106, A1104, A1085, A1095. Let's take a look at them in order of most desirable to least:

1. A1139, April 2006. Sometimes called 17" DL. This is the mother of all G4's. This 17 inch Powerbook has the fastest bus speed (167 mhz with 333 Mhz memory,) the fastest processor (1.67) a dual layer DVD burner, 128 MB dedicated graphics, 1680X1050 resolution (a great resolution even today) and up to 2 GB Ram. It has a firewire 800 port as well as a Carbus slot for expansion. 1000Base-T ethernet, airport extreme card, and you can even find them with a 100GB 7200 RPM drive. The keys even glow in the dark. In short, this is the top of the line, but also the top of the price scale in terms of buying used. Be prepared to pay through the nose of this beauty queen (it initially retailed at $2499.)
   
2. A1138, February 2006. Sometimes called the 15" DL. This is essentially the same laptop as the one above, only it has a 15 inch screen instead of a 17 inch screen. Even though it is a few inches smaller, it keeps a high 1440 X 960 native resolution for plenty of working space. This is a desirable Powerbook (the best 15" available) and so it will have a fairly steep price tag as well.
   
3. A1107, October 2005. I like this one, but it does have a few drawbacks: it is not as high of a resolution as the dual layer 17" (max of 1440X960,) there is no chance of a 7200 RPM drive (unless someone added one,) it only burns single layer DVD's, and the RAM is a little slower. It still represents a decent value when compared to the 17" DL because you can get a better price on it (that DL model goes for a premium as the best Powerbook ever!) And even though the DL has better stats, according to Geekbench tests the two perform fairly similarly.
   
4. A1106, February 2006. Here we take another step down, but how far down depends on the configuration of the model you find for sale. It is very similar to the 17" above, but unlike the DL 15" this SL 15" has a native resolution of 1280X854. You would want to find the 1.67 GHZ model (it also comes in a 1.5 flavor) because it's the 1.67 that also has 128 MB of video RAM instead of the 64 found in the 1.5 GHZ. Amazingly, the 128MB video version benchmarks only about 4% slower than the 17" above, which benchmarked pretty darn close to the Numero Uno at the top. You can get this one cheaper than the DL 15", too. I would probably avoid the 1.5 GHZ model of the A1106 with the lower video RAM in favor of option 5...
   
5. . A1104, May 2006. This is the 12 inch, 1.5 GHZ model. It only has 64 MB video RAM, though it is dedicated RAM, and maxes out at 1.25 GB of RAM. So why would I think it is a good buy if it is slower, lower RAM'ed, and has less video power? Unless you have ever worked on a 12" powerbook you don't know the joy of having a computer that you can easily carry on the palm of one hand. It is the ultimate in mobile computing. You can carry it anywhere, the battery lasts forever, and it has just enough power to run the types of APPs you are likely to want to use in portable situations. You can also hook up the DVI out to an external monitor and get resolutions up to 2048X1536 if you want to. The portability makes this computer a real winner.
   
6. This is the spot for the rest, the A1085 and the A1095. There is nothing inherently wrong with these and they are very similar to options 3 and 5 above, but you have to be more careful to get the 128 MB video option and the 5400 RPM option (or you may end up with 64 MB video on a 4200 RPM drive.) I have also heard that these models had a weaker ambient lighting system (which makes the keyboard glow) but I haven't seen it myself. I am shaky on these two models because people seem to price the desirable ones and the undesirable ones very similarly but it requires a lot more research by the buyer to be sure he/she is getting the proper one.
   

So there you go. That's my opinion on the G4 laptops. It should be known that I am writing this article on my "option C" right now next to my wife, happily tapping away on her "option E". Even though the new Macbooks and Macbook Pros can run rings around these G4's no Mac will ever feel quite so "Mac like" as the good old Motorola processors found in the Powerbook line.