Had a read through and a few folks are saying that the N900 is a terrible phone.
Yes it is. Think of it more as a mobile PC with a phone attached and you'll realise how brilliant this bit of kit is. iPhone beater, definately.
I upgraded a few weeks ago and got the iPhone 3GS 16GB. It was terrible, like every other Apple product that I've tried/tested/owned. It just felt like an overpriced polished turd. Sorry, descriptive words fail me today
I returned it and got the Nokia N900. This is were it's at. It's specification is similar to the iPhone, similiar processor speeds, screen resolutions, memory etc but the possibilities are endless. There's loads of development going on and the Maemo OS is pretty cool. Does feel a little like work in progress but they're getting there.
www.maemo.org - loads of news and loads of apps, which are free and can be downloaded from the phone via repositories (none of this installing iTunes to be able to do anything).
I highly recommend it.