If you have a picture editing website that is free to use, post 'em here! The one I used to use, Picnik, closed recently and I need a new one. Post away!
Photoshop is expensive. You can get PS CS5 30 day trial, though... GIMP isn't so bad, just need to use it more. Paint.NET is another program, but I don't like it. There's also PaintTool SAI (not free), but it's more for artists/drawing... This looks like it might have other suggested programs, too: http://graphicssoft.about.com/od/pixelb ... otoedw.htm I don't really know about sites, because most I ever used - which wasn't many - really sucked.