What are some good wireless internet providers? (Can't get Verizon and won't get Comcast)?

I live in Philadelphia where Comcast practically owns the city. I have a lot of issues with their internet (I used to have it) and am an need of a new internet provider. I have looked up Verizon but it is not available in my area. Earthlink only offers dialup and we need wireless since we have multiple computers in the house. Thanks!