Like N8than (the name for my N810) for navigation on the highways with MaemoMapper...when I have internet access to get the maps needed for the area I am in - which is rare.
It holds all my passwords for all my account with Passwiord Safe.
Using MyTube to view videos on YouTube of Yamaha PSR-E413 electronic keyboards (my latest investment) and Christian videos.
Aisleriot Solitaire for a quiet card game. Barrage when I want something noisy and want to blow something up.
Firefox browser for surfing the web. Pidgin Internet Messenger to access all my IM accounts with one program. And of course, use Skype and also to keep tabs on my Google Voice.
Chiaowl is my better half and when her battery goes dead out on the road, I let her use my battery to keep doing what she does...more than I do...while her battery charges in my unit....only so much I can do while driving. Thought about selling it. Thought about just giving it away. Glad I didn't do either Chiaowl may have to send hers in for repair...N8than can keep her company while the repairs are being done. :-)