I was on a favorite site of mine where I always something interesting or funny and came across a link about an artist. This guy has some pretty cool stuff. Check it out. Some them are more simple in the sense that they are not necessarily "mind bending" but some them have a a serious twist which you have to really look at the piece to see.

http://thechive.com/2012/06/20/mind-bending-surrealistic-paintings-by-rob-gonsalves-32-photos/