Don't know how common this is but I've had a Pi running for 35 days 6 hours (so far). With over 80GB transferred on my half assed comcast cable connection.
Not bad for $25 a credit card sized board sitting in a cardboard box in my broom closet.
I think I'm going to give one to everyone of my family members preloaded with Tor. Plug it into their cable router and let it run.
That would be another 4 bridges added to the total. If we could get another 100 people to do this it it might be a good way to add capacity with very little cost or power use.
BTW, I have nothing to do with the Pi foundation, I just like playing around with them.
Richard