Scripts to authenticate with Wifi "hotspots"

[Matt Good <matt matt-good net>]

I use AT&T wifi from Barnes & Nobel, and the free wifi at Panera Bread.
Both require authenticating yourself via a web browser by redirecting
your initial request to their own site where you submit a form to sign
on.  

Is there a way to have a script that runs when connecting to a specific
network?

Has anyone written a script to automatically sign on to a wifi service
like this that I could customize for the services I use?

-- 
Matt Good <matt matt-good net>