Thanks for doing this, they are amazing and super-relevant.
Ideas:
@ev/@jack on twitter
@tonystubblebine on crowdvine
@joshu on delicious
chris dixon/caterina fake on hunch/flickr
pg on viaweb
kevin rose on digg
steven chen or chad hurley on youtube
andrew warner on mixergy (recursive intervews, perhaps? :)
craig newmark on craigslist
jason fried on 37signals
that's off the top of my head anyway.