I just started a tumblr where I plan to list common mistakes in UX-design so that we, together, can become better at designing websites and apps.
It's available over here: http://common-ux-mistakes.tumblr.com/
Tell me what should I cover next, or do you want to help out in another way?
Note that I'm not really a UX-designer, I'm just interested in the subject.
Also, i'm looking for someone to design a tumblr theme so that we don't have to go with the standards.