I'd agree with everyone else --- I've got an N810 I picked up on eBay last fall that I carry every day, in lieu of a laptop, unless I'm in hardcore edit/compile/debug mode and need to squeeze every last minute out of my rail commute. When a second came up for sale, I bought it as a backup unit. At home, we have an older, very beat up N800 serving as the kitchen Web Radio / weather / news panel on top of the microwave plugged into a couple of speakers.

With it and a Bluetooth keyboard, it's all I need for light email, quick checks to twitter, composing the occasional memo for work, reviewing work & home PDFs, and the like.

The app community has been great --- I've installed a few apps, but find I really only use an HP calculator emulator, emacs and pc-connectivity, and occasionally maemo-mapper for amateur radio stuff.

Others have remarked that the browser can be a bit on the pokey side; that's true, but especially if you go to sites optimized for iPhone, it works really well.

If you can afford it, I don't think you'll be disappointed.