Google AdSense referrals -- If you refer someone who joins the AdSense program, when they earn $100 you get a $100 referral bonus.
Google AdWords -- get $20 for each advertiser that you refer.
Firefox -- Get "up to $1" for each person who downloads Firefox with Google Toolbar.
Interesting. Makes you wonder what the toolbar's going to turn into. (Browser... we don't need no stinking browser.... we'll just take yours & make it work the way we want it to...") See Micropersuasion.