Wow, I actually know this answer from a web-conference they had last week. The 4500, 6500, 3550 Catalyst switches and the 3700 series router all support inline power with the right version/modules. The 2950 does not.
However, you can do "mid-span" power by putting in a power-injector and I believe there are 3rd party patch panels that do power-injection also. So anything is possible.
