Wireless access point association daemon?

[Thomas Hood <jdthood@yahoo.co.uk>]

I have a laptop with an 802.11b card.  When I am in the vicinity
of an access point (AP) I can see the AP's details by running
"iwlist IFACE scan".  However, in order to associate to APs 
with encryption switched on I need to set the encryption key
using "iwconfig IFACE enc KEY".

My question is: has someone written a utility that will do this
automatically -- a utility that will set the encryption key 
according to the access points that show up in the scan?  

I have searched the web for a while and what I find are sniffing
and cracking programs.  That is not what I am looking for.   I
am not interesting in collecting packets and I know the
encryption keys I need to access these networks.  I just want
a program that will automate the process of association.

I could write this program myself.  In its simplest form it can
be done in one line of shell script.  However, making the
program work reliably would take more work.  I would like to
know if anyone has already done this work for me.

TIA for any tips you can provide.
--
Thomas Hood