Thanks for your suggestions - I'm actually already using a cookie that stores the session ID, which points to a user table in the MySQL Db and I didn't even realize I could pass other variables - duh!
I actually went with the Javascript option, though, since I want my cookie to be as simple as possible (basically just storing the session ID) and I don't want the backend database to have too many fields. The submit() method works great on a simple HTML page that contains a form with hidden fields!
Thanks again...you guys rock!