Here's one for ya. An app to check which part of the world is illuminated by the Sun, and to know when the sun sets and rises. Works on all Series 80 models (9210, 9210i, 9300, 9300i, 9500).
So, what is it exactly?
It shows a map of the world with one part illuminated and one part darkened. There is also a sidebar which lets you know when the sun sets and rises, Moon illumination percentage, and also today's date.
This was a really educative project for me to learn about Symbian C++ and chronometry. I designed and coded the program in a way which enables you to run it continuously forever without going inaccurate. Well the summer time dialog goes invalid in 2050 but drop me a line if you need it extended when the time comes 😉
The app only needs one thing before it begins to work accurately: the summer time (a.k.a daylight saving time) your country is using, if any.
Grab the SIS installer file here! - v1.02 ~750 kB
EDIT January 2, 2010:
With the year's change the month changed to January, and I discovered a significant bug in the application: when the clock reached some time (e.g. 2 p.m.), the map started drawing weirdly, leaving a gap into the daylight area, like this:
The problem only occurs in January.
Link to the new version, v1.02, is above, so get it there to get rid of this bug.