Check with your cellular provider--- most offer a data access bundle (you might already have it) which lets you access the Internet from your cell phone, as long as your cell hardware is up to specs. I use Cingular and have two cell phones--- a Motorola v551 for personal use, a Nokia E62 (similar to a Treo) for work--- both get Internet access. I have the cheapest plan on my personal cell and unlimited data on my work phone, and use both for web-based email when I don't take my laptop on a trip. It's not always pretty, especially on the Motorola's tiny screen, but it gets the job done. Just be careful with the plan you choose; the monthly data bundles can be quite affordable but depending on the carrier, the overage rates might be painful.

You can always add the data service for your trip then cancel it when you return. I've done that for other cell services like International calling. Usually your carrier will want you to sign a new 2-year contract when you make these changes but I really like Cingular so that isn't a deal-breaker for me. Or get a pay-as-you-go plan on a PDA-type device that is more suited for Internet access: Treo, Blackberry, Blackjack, etc.

The coverage I've gotten from Cingular has been consistently very good, with few dead spots in the US or Canada, and if you get a good device, you'll be surprised how functional the mobile browsers are.