Nice, mine is rev 2101.

Firstly, congratulations on getting the most awesome phone + h/w keyboard ever produced. As you've already discovered, this is also the most awesome community ever.

If your seller has 99.7% rating and missold you, I'd ask for $40 back in exchange for a 5* rating. Make a big deal out of the misselling and tell him you'll give him a negative rating otherwise.
It's probably worth $40 to him just to avoid that negative rating.

You can't be warned enough about the USB port. I've broken 2 now.

The only other big flaw of the N900 is that it only has 256MB memory which Maemo takes up roughly 120% of. Yep, 120%. If anyone ever produced a fake working N900 with 1GB memory, they'd sell like hot cakes.

There are currently 3 good ways to ameliorate this:
1. CSSU Thumb. This is a version of CSSU with pretty much perfect track record and full functionality yet is a lot smaller footprint.
2. Your N900 is going to swap regardless. By default, it swaps to internal flash. This is slow flash and will wear out its flash cycles. Investing in a microSD card with fast writes will be your second investment though it needn't cost much. Also, when the N900 runs out of swap space, it'll become unresponsive for 10+ seconds. FlopSwap can fix that without rebooting.
3. Conky will tell you what's hogging your memory.

Most of the good software on N900 is third party and not very well catalogued. There's software for pretty much everything and probably the best way to find it is to ask on here.

I use my N900 mostly for browsing (Opera), taking notes (Quicknote), spontaneous photography (Bless N900), alarm clock (SleepAnalyser and EvilAlarm) and ofc the phone.

Lastly, don't buy into that SpeedPatch BS.