Easy, but not really the cheapest (unless you already had all the stuff anyway...) use the "MicroSD" card. I save all my pics to my card (got a 4gig for pretty cheap, you can get 1 or 2 gigs for under $15 now) and then use a USB card reader to plug into my computer. That is the most efficient way for me.
A cheaper way (cheap if you have unlimited TXT) is to email it to yourself. Send the pic via email by entering your email address instead of a phone number as the recipient, in the TO: field, instead of 235-532-5325 just put "
jmassari@gmail.com" (or what ever address you use for email). Still another way is to send it to your Twitter or Facebook (for, sign up at TwitPic.com and send it to the email address they give you)