Despite my liking the commuting forum a lot, I work from home, so commuting by bike would just be an exercise in silliness! For me, all that grocery shopping and running errands to bank, post office, and library, IS my commuting.

I find using the bike for this is very freeing, since before, I'd let it all pile up so I could do everything and cart home a car-full of groceries, so that I could use gas most efficiently. Now, instead of big grocery trips, I just make frequent grocery trips. When the sun rises early enough for me to restart my pre-breakfast funxercise bicycle trips, I can hit the store when absolutely nobody else is even there, so that it's practically my own personal shopping paradise!

Anyhow, for me, the constraints involve time, rather than distance, since a home-based business doesn't do much business if one is not at home...