This past fall, we purchased an unlocked Novatel 2372 MiFi. This unit connects to cell phone towers and gives you Internet access.
The advantage of the MiFi over a rocket stick or air-card is that it creates a wireless hot-spot and allows up to 5 devices connected at the same time. This hot-spot has an advertised range of 30 feet but the signal seems to extend further than that and we have been able to allow a neighbouring vessel to connect through our MiFi by giving him the code.