Here is an interesting web application called Sumo paint it is an online app that is very much like Photoshop. It actually got some very interesting drawing tools like symmetry which make it east to draw a wheel rim design. It is actually an interesting app to draw sketches in but is not a real photo editor but more a sketch and drawing program.
It is totally free and you don't have to install anything to use it just register and log in. Also you can publish your artwork in their website. If you are interested in using this app to go sumopaint.com for more information and to open the app directly click here.
However this is where the future is going all the software we want will be on the internet and we don't have to install anything. Just bookmark them or even make special icons on the desktop to acces those sites easier and directly.