As a matter of fact I'm running into this exact problem right now. RSS, SOAP, XML, why can't I just:

wget http://weather.com/api?field=temperature&zip=02142

and get back a file consisting of "52" or something similarly simple.

Currently I have to get a 1k+ file and create a parser for it. I can't even find a really simple format that would allow me to use prebuilt XML parsers. If anyone knows of a dead simple API for temperature, precipitation, etc., I will upmod you at least once.