different page templates depending

I'm interested in multiple page views based on node taxonomies

For instance, how, on the node level, do you choose a different page.tpl.php based on a particular taxonomy term? So /node/4 has taxonomy /taxonomy/term/1, how can you tell that node to use the theme of /taxonomy/term/1?

And if this can be done what will happen on a node with multiple taxonomy terms?

I've found this http://drupal.org/node/104316 but I that only seems to work for different paths. But would there be a way to use a /node/4?varx type url string to do this? If so any ideas how?

Thanks
IrnBru001