Scripting is the foundation for everything the moves besides a avatar operated by the cursor keys.
Now in december 2006 we use LSL - linden scripting language , but soon in 2007 we will see more possibilitys.
if you have at least a small programming background or are not affraid to learn, jump in the several resources and take a few days to learn what you can do with it.
and, there are some strange things you will see. (not able to write data somewhere in world) and clever workarround (change prim properties to use it as storage).
Scripting LSL Wiki http://www.lslwiki.com
external Database for use with LSL http://w-hat.com/
Second Life Developer Library http://www.libsecondlife.org/
overview for LL resources http://secondlife.com/developers/resources/matrix.php
Forums http://forums.secondlife.com - these are at the moment maybe the best place to put question or discuss solutions
If you into SL - RL communitation via web and SQL, have a look at this: