Challenge for November: No Google Software. That's where I'd have trouble.
Mail: gmail is integrated deeply into my workflow. Hard to live without it.
Money: Adsense pays for my hosting bill so can't drop them, besides there is no worthy competitor with Adsense (for small blogs)
Analytics: Google's product is great and free but i would be very happy to try some alternative.
Docs: don't use google docs a lot. Not important.
Calendar: I have too few plans/appointments so a calendar is useless :-p