My employer encourages it somewhat. The nixed the shower due to cost concerns at our new building (it's a small tech startup), but they did put in a bike rack. Of course, nobody uses the bike rack, we just park our bikes indoors in an area by the vending machines. At any one time, there's between one to five bike commuters in an office of about 40ish.
I did get my manager to start biking to work more. He even went out and bought a pair of Axiom panniers so he could ditch the backpack and not worry about his stuff getting drenched in the rain.