Really useful post on how to reset / reformat Nokia phones. *#7780# - Restore factory settings and *#7370# - Reformat. Handy dandy.
A bunch of dictionaries for Symbian devices, including Spanish to English. :-)
The podcatcher application for Symbian, the successor of Escarpod.
How to install Nokia's internet radio application on the E52, E55 and E72. Reports that it works.
Open source media player (supports mp3, ogg, and more) for Symbian devices. Great for the E51, much better than the in-built player. Supports skip forward / back... :-)
SSH client for Symbian OS for phones like the Nokia E51 and E52.
Download maps for the Map application on the N810 tablet without using the in-built software. Very useful. :-)
A bloody handy little perl script called tablet-encode which automatically transcodes video files into a good format for the Nokia tablets. Even has a GUI (which doesn't work for me) through gtk2-perl. :)
Claws Mail is a lightweight mail client. The maemo port is specifically for Nokia tablets and supports advanced features way beyond the default mail client, such as imap folders, etc.