Simple AJAX callback I'm looking to a way to make a call to a PHP function in my Drupal 6 module, and return the result asynchronously to the page.

I'm familiar with jQuery AJAX, but I don't understand how to post to a function using it. Does anyone have experience on doing this?
Disclaimer: I've never done this with Drupal 6.

You want to use a menu callback: You create a menu item (which is just a path associated to a PHP function), and point your query request at that path.