You can also use TinyPic.com if you want to upload pictures without starting an account. Just find where the picture is in your computer, open TinyPic, and then click the 'Browse' button next to where it says File; click the green Upload Now button, and then when the new page comes up scroll down to the last URL (the lines of numbers and letters are URLs, the web address where your picture is held now) and copy it. Then, activate a new post here; type [IMG*][/IMG*] without the *s and then paste the URL right in the middle, like this: [IMG*]URL[/IMG*] (Again, without the *s) Your picture should show up then, but you can always do it without the tags and just post the URL for people to click on.
Hope that helped. =)