You can also use most cellphones as a modem (dialing a land-line, though speeds are horrible), or directly on a GSM network if it's supported by the phone, service provider, and network (I know AT&T and T-Mobile do, though it's mostly only in big cities in the US).
Although if you're *really* in the middle of nowhere, you probably won't have cell coverage, and will be way too far away to get Wi-Fi. Satellite is then your only option, and will not be cheap, since you need a two-way link (most satellite ISPs only provide the download via satellite; uploads are handled via a dialup link).