Citrify, iPiccy, PicMonkey, Ribbet, Picadilo, Fotor, FotoFlexer or Lunapic are great all round web based and FREE editing tools.
Fotor is the best if you use multiple systems as has companion apps for the iPhone/iPad, the Android, Macintosh, Windows and Windows 8. Fotor allows you to edit your photos with a wide range of looks, to add fancy borders, to create a collage or simply fix some imperfections. Unlike Citrify, iPiccy, PicMonkey, Ribbet, Picadilo it is a small download - but well worth it.
Adobe, makers of the expensive Photoshop, has a free website version in Photoshop Express. If you need/want more features downloading GIMP is a great options. Still free, but you have to download the software.
http://www.edit-photos.net
http://www.squidoo.com/fotor-photo-editor