Image shack is a free hosting site. I use it a lot for forum posts.
Not sure if you need to make an account or not, I can't remember. But if I'm using it, it's nothing too difficult. :)
Once you have uploaded a picture, choose 'full view' (or if you can't see that option, click on the picture, then right click and choose 'view image').
Then copy the url for that.
Then click the little yellow picture icon from the menu here, backspace to get rid of the http already there, paste your copied url and hit 'ok'.