Indeed the trick is keeping up with changing websites.
Many programs are easy to query, but some (like AA) get a bit trickier.

So far I've been able to query the following programs balances successfully using vbscript/javascript:
qantas
JAL
airmilesmart
continental
northwest
asiamiles
ebay anything points
goldpoints
mypoints
epoll
erewards

not working yet (of course these are the most important!!):
american
delta
united
usair

I'm trying to develop an xml-based query system, that should be easier to modify than requiring a new binary update.