I want to insert a bit of JS (AdWords conversion tracking code) at the bottom of the page when someone registers on our site. I can use hook_user to catch the new user event, and I can use hook_footer to stuff HTML/JS just before the </body> tag. However I need to set a flag or something to tell hook_footer when to do its stuff.

I've tried using a global, manipulating $GLOBALS and even $_GET directly, a static variable insdie a helper function etc. but I get the feeling I'm missing a trick.

Any suggestions on the "Drupal way" of doing this most welcome!!!

Oh, and there's a beer waiting for a solution! 

Cheers

Giles