hacking wp_insert_post

hiya,

i’ve installed my fair share of wordpress sites now and need to install wpmu for a client. so far all seem ok, but i need to post stuff to the client’s main site when a blog post is published.

i can easily hack a function which send a http post (via curl or something) when triggered. but how can i trigger this without hacking the wp-admin wp_insert_post function? can i do this with do_action? if so – how?

all suggestions welcome. i’ve found nothing on the www…