in gnome terminal, CTRL + I is "tab" for filename autocompletion

CTRL + FN brings up special symbols missing on keyboard

If your N900 is bricked and battery is dead, you cant reflash OR CHARGE BATTERY: You must get another charged battery or external charger (mine was 27euro)

Keep an eye on your free space on the root filesystem with the "df" command. Do not allow this to fill up. User data should be somewhere under MyDocs

If you find something broken or not to your liking, contact the author or maintainer or file a bug report. if you are used to other commercial products, your inclination might be to first whine about a problem in a forum such as this one. In the case of Maemo and open-source apps, you have an opportunity to directly improve applications and help shape the future in a positive way.

That is an amazingly empowering feeling, and it is the most important N900 "tip" that i can pass-on.

cheers