My background includes criminal justice studies, forgeries and fraud investigations.  I wanted to offer some very basic tips for avoiding identity theft to anyone who may be interested:

1. I don't recommend sending a check even if the seller accepts them because it is too easy for dishonest people to steal and duplicate your information.  Money orders or cashier's checks are best because they don't include your personal account information. 
2. If you use checks anyway (whether for eBay or elsewhere), consider having only your first initial and last name printed on your checks.  Your bank will know how you sign your name, but a potential thief will not.
3. Never print your social security number or driver's license on your checks.  Years ago, many people went through a phase of having some or all of this information on their checks.  Today, having this information on your check can make you a target for identity theft.
4. Particularly keep your social security number confidential.  Insist that ANY company (schools, doctor's offices, etc.) that use this number for ID purposes to provide an alternate number.  It is your right to request this.
5. Never respond to calls or e-mails requesting your personal information.  If you are in doubt, hang up and call the company directly.  Never put your credit card, social security or other information in an e-mail.
6. If you buy or sell on eBay, the best idea is to get a P.O. Box.  I don't recommend the USPS boxes simply because their usage is limited.  Companies like UPS will not ship to a PO Box.  However, if you get an independent mailbox through a company, you can use it for everything.  You may not live in a large, metropolitan area and may not think this is necessary.  There are many reasons to have a P.O. Box and I do recommend this to everyone who buys and sells on eBay.  You don't have to worry about theft of your packages or being home to sign for a package; there is always someone available to sign for you.  If you live in a rural area where your mailbox is on the street, you definitely need a P.O. Box.  The benefit is not only keeping people from getting your personal information by going into your mailbox at home, but also that you will be giving out an address other than your home address for the DMV, mail, checks, credit cards, etc.  It is simply a superb safety precaution!  USPS delivery confirmation isn't always reliable, but if your item(s) are shipped to an independent address, you will unlikely build a rapport with the employees of this company and that will provide you with more backup if/ when packages are not received.  It is a large bonus that these independent mailbox companies provide a street address in addition to a box #; you may have noticed that many businesses ask for a street address. 
7. Check your credit report regularly; be certain that all addresses (including former addresses) are correct.  Dispute any transactions or information that is incorrect immediately.
8. Do you receive preapproved credit offers in the mail?  Take yourself off these lists in order to safeguard your personal information!  In the U.S., you may do so by calling Consumer Credit Reporting Opt Out:  888-567-8688.  This call is computerized and if your name is more difficult to spell than "Smith," it is possible that it may take you a few minutes, but will be worth your effort!  Note that you will have to give your social security number and date of birth for them to remove you from this list.
9. Photocopy the front and back of all your credit and debit cards.  Keep your copy in a safe, locked place.  If your wallet is lost or stolen, your information will be readily accessible (including those elusive customer service numbers often on the back of credit cards- not a great place for them to be when you no longer have your credit card).  To avoid potential responsibility for charges, be certain to cancel your cards immediately when you discover they are missing.  Likewise, notify your bank immediately if your checks are missing.
10. Do not write down your passwords or PIN numbers.  Memorize them if possible.  If that is not possible, keep them under lock and key.  Do not keep this information in your wallet or purse.
11. Active duty in the military?  Place an active duty alert on your credit by contacting the three major credit monitoring agencies:  Experian 888-397-3742, Equifax 800-525-6285 and TransUnion 800-680-7289.  They will take special precautions for up to one year if there are any applications for credit in your name.
12. If you become a victim of identiy theft, you can call the Federal Trade Commission for assistance:  877-438-4338.  If you become the victim of a forgery, contact me for a referral or assistance.

Be well, be safe...

... and no speeeding!  :)