If you buy a lot on the web using PayPal you may want to look into their new Security Key, available at PayPal.com for $5. It generates a rolling 6 digit code which you add to your password when logging in. Even if someone manages to get your user id
and your password, they won't be able to get into your PayPal account without the 6 digit code. Well worth the $5 IMHO.
Disclaimer: I am in no way connected with PayPal (other than using them way too much)