Faceblr

I like your idea but I am afraid it may not be eye catching enough. I only say this because there are at least enough people on Facebook that have drawings for pictures so it may not be a dramatic enough change. Granted I don't know your personal Facebook page or tumblr so maybe it will be impact full but that was my first thought. I do like the idea about analyzing the difference in the two social media websites but I just think it may not be enough to really get enough data. Maybe try making your Facebook page feel like tumbler and vice versa? That may help with the shock value.

The idea to switch profile photos is very interesting. It is easy to analysis people's different expectation on others when choosing different social media. Maybe it can also reach a bigger idea about how people act differently in different situations. It's quite similar with the difference between reality and internet. Also, I wonder that since there are not enough people know you who really are in tumblr, will there be enough reaction from others to analyze? Generally, this is a great and entertaining idea.