A pain, but can be done.
Simplifying options, there are two ways to do it:1. The 'Old' Way - You need a laptop ($400 to $4,000), cell modem card (~$200), cabling to the particular model of phone (~$50) and of course a phone. Do a search on the net, there are people who sell all this stuff. This setup, as the best I can determine, will only work when your phone is on an analog cell network.2. The 'New' Way (a.k.a. what the cell companies want you to buy) - In this setup your phone, through software on the laptop, acts as the modem. So you need a phone with this capability (e.g. a phone with Sprint Wireless Web)and a cable & software (sold by Sprint for $100). AT&T, from what I can tell, is behind in this technology, but other phone companies may offer it besides Sprint. BUT it will only work in digital cell or PCS systems.So... where will you cruise? Near the big cities the cell networks are digital, but outside that it is generally analog. For example, on the Gulf coast, around Houston, New Orleans and Tampa is digital while the rest (70% of the coast) is analog (& probably roaming & more $$$). I assume a similar situation would exist on the East Coast.If e-mail is all you want, then the best solution might the the hand held e-mail devices reviewed in last month's Practical Sailor.