(caveat - most people may not be using these NOW, but they will be after I post this)
1 Make tshirts
I’ve got this awesome t-shirt that lets me program stuff into it. Its got an LED display and it basically rocks - for those of us that can’t get the electronic version though, have you ever considered printing your ISBN on the front of your tshirt?
Quirky, and helpful, it’ll let anyone interested in your work have the ISBN number of your book, plus its incredibly photogenic, and scores massive geek points.
(the other four are at Publishhacks)
I'm curious how others promote their books though - have you found any highly successful methods or something that really doesn't work? Share it please!