Getting a posts taximony

I have a plugin which uses custom post types to create posts.

What I need to do is run an IF statement based on what catories these posts are in. However they are custom post types and use taxomonies to create these categories.

How would I got about finding a custom posts taxomony?

In my phpmyadmin I can easily find each individual taxomony and each post but I cannot see how they link together, otherwise I’d use some SQL to manage this!

Any help would be great. I’m using the latest wp-ecommerce which is creating these custom posts.

Thanks in advance,

Versi