One of the joys of living in Washington is biking to work. DC is a very bike-friendly city, with lots of off-road bike trails, on-street marked bike lanes, bike racks and company programs that encourage employees to commute by bike. If you don't have your own wheels, the Capital Bikeshare program is a wonderfully popular option.
Since returning to DC, I've been commuting 4 miles each way from our house to the Foreign Service Institute (FSI). Some of my colleagues commute 10 miles or more each way. FSI has a nice little gym with showers and plenty of bike racks. There's even a DOS bicycle benefit program that pays you a small reward ($20 per month) if you forego any subsidized parking passes or Metro benefits.
Not only is biking an environmentally-friendly way to get to work, but the health benefits are awesome. It's a free workout to and from work. Mr. Crab has lost 7 pounds since he began commuting by bike.
Unfortunately with morning temperatures in the low 30s, it's now getting too cold to bike. Some of my hard-core colleagues are still riding, but Mr. Crab is not a fan of extreme temperatures. That said, as long as you "kit up" properly, you're ok. You don't need to spend to much money to keep warm. Instead of the $200+ biking pants and $300 bike jackets, I spent about $50 for the REI jogging pants and another $70 on-sale for a Pearl Izumi windbreaker. Underneath, just wear layers of whatever you have around the house. I usually wore my old ski base layer (thermal underwear).
The only annoying part of commuting by bikes are the rude A-hole drivers AND bicyclists. Too many drivers who think they own the road; I've been cut off several times and nearly got "doored" one afternoon. One woman in a minivan in particular has turned in front of me on two separate occasions; next time I'm taking a photo of her car & license plate and posting it here. And then there are the idiot cyclists who think they are above the law, failing to stop at lights or passing without giving an audible warning. Still, we're looking forward to spring time to start biking again.
If you're just starting out, some good biking resources in DC include the Washington Area Bike Association and Bike Washington. And local REI branches offer all sorts of courses such as bike maintenance. Don't miss the Mount Vernon Trail, which runs along the Potomac River from Teddy Roosevelt Island to Mount Vernon Estate.
A few photos from my daily commute: