i was going to vote for option #4, but seeing how everybody likes them I voted for option #3. they overlap with the items in the scroll area and that looks bad. especially with the right-hand cd-icon on the bigger items. doesn't look good.

my opinion is, they should be thin. really thin. if you can't/don't want to flick your finger to kinetic-scroll, use your fingernail to move the thin scrollbar :P i don't think finger-friendliness is necessary there, just takes too much space no matter what you do.