Gmail does work, but you'll need to use the basic interface, without the monotonically increasing numbers of bells and/or whistles. And it's slow.

Do you never find yourself in hotels where you can't connect to the internet with the iPad? It happened to me just this week at the Ritz Carlton in Singapore. Their login page requires some pop-up, possibly flash-based functionality, which won't work with iOs devices. I don't think an Airport Express would have helped either, although I didn't have one with me to try.

But even if I could rely on the iPad for everything else, I'd still use the Kindle for reading.