The UI is possibly nicer than your cell, though I too have gotten pretty good at "dialpad text entry" on my cellphone.

I'm using the N800 for:

• A quick surf on the couch (more convenient than my PowerBook) for checking on an auction, forums, imdb during a movie, etc.
• Less obtrusive to bring into a meeting to surf for facts or connect to my desktop and pull up a document
• Hanging in the airport (games, surfing, etc)
• Keeping a shell open to a process running on a remote machine while I wander in/out of the lab
• Bluetooth on the road when I'm away from my CarPC
• Storing tech docs while at a customer site
• Audio note taking

Like you say, yes I could do all this with a laptop, but why lug 8lbs around when I can get away with a whole lot less? Sure, I'm not going to write a spec on it, or even do a post this size to a forum, but I've made notes in code during a meeting; started a build; programmed my TiVo; cleaned up a customer's hacked install...

I like the lil' fella'. But it may not be for you, and that's why you've got a return policy.