Our organization occupies two adjacent suites at our downtown location. I work in the smaller (much smaller) of the two suites. It's known as "The Annex". Along with housing about 10 people, "The Annex" has become the default bicycle garage for the organization.
On nice days, you can find as many as 10 bikes crammed in back here. There are a few people who keep their bikes where they're supposed to (in the bike room down stairs), and one or two more who keep them in their office/cube or outside but this is where most of them end up.
A slight majority of the people who spend their day in the Annex are regular bike commuters. This is a far larger percentage than the organization as a whole. We recently had someone move from the larger suite into this one. He too has now started riding his bike to work, - at least part of the time.
My theory is that working amongst all these bikes and bike commuters has given him a little push. I'd also argue that one of the reasons more people don't ride their bikes is that it's not seen as "normal". Funny what can happen when all of a sudden it is.
So while there are certainly practical considerations to deal with when it comes to motivating people to ride to work, the power of making it seem more mainstream can't be discounted.
On the one hand, I'm a little irked that the Annex is viewed as a storage area by the rest of the organization, and it's not just bikes. On the other hand, I think the visibility of these bikes has contributed to getting other people to ride.