The idea of it was great but the phone itself was pretty frustrating.
The idea is that it was a little bitty linux tablet, with something of an open source community behind it, that could also make phone calls. I explained some of my thoughts in this arstechnica thread[0] from 4 years ago.
But the reality once I got the phone was it was just slow and frustrating to use. Aspects of it were great (it multitasked the best of all the phones of its day), but over time it's glitchyness (hanging up on calls instead of answering them, because the buttons jumped around), and the lack of multi touch brought me down.
I still have my N900 in a box somewhere. If anyone in the Boston area wants it, ping me (email address on my profile here) and I'd be happy to give it to you.