I gave a little, but then I have given a little to a number of the candidates. Giving gives you access (and makes your phone ring off the hook).
The most enthusiastic and well organized campaign I have seen thus far is Obama's. McCain's seems very fly by the seat of your pants. Clinton's is slow and steady (Patti Solis Doyle is doing a good job, but just doesn't have the groundswell to work with right now).