Actually you dont need powerful hardware, I run Gridcoin on a Raspberry Pi! You can do BOINC work on PC/MAC with Windows/Linux/OSX, you can use Android phones/tablets, laptops, whatever you have pretty much except for iPhone/iPad because Apple lock them down.
Some people think its not worth it to use low power equipment, but every single result you return is one that someone else does not have to work on, so even if you can only do a little bit, its worthwhile from the humanitarian perspective.
Very good points, I shall get on this with more than just my main PC.
Cg