I would take a look at the Gerber STL 2.0 (Doug did a mini review from one of his Shot Show reviews - http://www.equipped.org/shot_show_2007_knives4.htm).

I have one that I orginally had in my PSP, but it found a way to my key chain till I had to fly out for a business trip. Then I quickly lost it after that lost it.

I found that its thin enough that it hides on the key chain unlike the SAK Classic which I find its a tad on the thick side.