You can plug in a USB 3G antennae (costs <$80).
All you need to do is slide in your 3G SIM card, and your good to go*

The biggest drawback is having the damn dongle on whenever you want to access the internet (or having it on 24/7 if you want push email/constant access).

*as long as the usb-stick is supported and the custom ROM you flashed supports 3G connectivity.

Has anyone preordered a Notion Ink Adam. I really want to know how that beast stacks up, is the UI fluid? usb host just works? PixelQi upto snuff?