Hmmm.. I have dedicated web space I use to host my images. Most ISP's come with web space. Basically, you have to find an internet facing host that you can save your picture to.
http://imageshack.us/index3.php
and
http://www.pbase.com are two options.
In some forums, you can attach the image. However I think that's restricted to the Photography and a couple of 'private' forums.