Internet service provider would be a huge step for Bitcoin. I think it would be revolutionary for Bitcoin.
It'd be quite easy, too (... well - for an existing ISP). Super-low maintenance compared to accepting cash. If there isn't payment on due date, the gateway user software simply locks the the user out. Pay monthly rate later, you're able to use the network again -- no fussing with CSRs.
Would be great with a WISP, and allow a dramatically more frictionless on-demand service.
As for needs, insurance is probably toward the top of the list. Insurance and an exchange serving the US which isn't always on the verge of being hacked or shut down. The cheap, easy-to-do reselling stuff is already covered.
