Zipweather is an example bot I made for micro-blogging services like twitter and identi.ca. Users reply to the bot with a zipcode and they get a reply back with the temperature and weather. You can test it here: http://identi.ca/zipweather
Since this bot uses PHP and CURL it is currently working only with status.net sites, such as identi.ca. Included in the archive is the php code and a script I use for starting and stopping the bot. It requires that php-cli and curl for php is installed.
Simple PHP Micro-blogging Bot
Zipweather: weather bot - zipweather.tar.gz