When I go to a SE site on my phone (using Opera Mini 4.2), I can accept an answer by clicking the text "accept".
However, after accepting, it still says "accept". Since the switch over to using sprites, I haven't been able to see any images. The only thing I have to 'click' on is the ALT text.
I propose that it be changed to say "accepted" when the answer has been accepted. That way I can tell whether it has or not.