I like tinypic better.. it's quick and instant and you don't need to sign up. (It's actually run by photobucket.. kind of a photobucket 'lite')
1> Go to www.tinypic.com
2> Click browse and navigate to the image stored on your hard drive.
3> Click UPLOAD NOW
4> Type the two captcha words and click UPLOAD NOW
5> Copy the following line:
[IMG]http://i52.tinypic.com/picturename.jpg[/IMG]
and paste it in your post.
6> Click PREVIEW to make sure it works. If so then click POST.
DONE!