Reusable reward systems
AJ of Thingamababy reminds us that toddler rewards (for potty sitting, toothbrushing, etc.) can be as simple as drawing an "X" on a calendar. The trick is finding out what motivates your kid, and then letting the reward do its job -- don't oversell it.
Jill's potty training reward system prompted a great discussion on this topic just last month. So many creative ideas!