Something fun that I found the other day:
Test My Brain
There are three tests:
1. Judging words and faces
2. How good is your number gut?
3. Can you name that face?
The first one has a number of parts. You are shown several words and asked your opinion about them. Then you are shown faces, and have to judge which one doesn't fit. Then you have to try and remember which words you saw previously and which ones you didn't.
The second one shows you colored dots, blue and yellow, really quickly, and you need to figure out whether there are more blue or more yellow. The second half shows you dots, but one of them changes color and you have to find it.
The third one shows you celebrity faces, and you have to try and identify them.
Each test scores you based on how well you did compared to the other people who took the test.