If you take public transportation, either walk a few stops further than where you'd normally board the bus/train, or get off a few stops early and walk the rest of the way. If you drive to work, try parking further away and walking the rest of the way to work.
If your commute is too long, try a Walk to Lunch Day instead: invite your colleages to go with you for a half-hour walk during lunch.
No matter what your commuting situation, try to walk (more than you normally do) on April 3. The goal is to get at least a half hour walk in (15 minutes each way).
The benefits are three fold: you reduce your carbon footprint, you get some additional exercise, and you participate in a national environmentally-friendly effort.
I've already roped in a few of my coworkers to participate. You should do the same. I'll be walking to work on Friday, April 3...will you?
Remember, tomorrow is Earth Hour! If you're in Brooklyn, join me at bushbaby to celebrate.