Mobile website / view full site

Does anyone know how to use WordPress to toggle back and forth between a mobile site and a regular site, while on the mobile device?

I've got a theme set up for the mobile device and detection in place to steer the user there once mobile is detected. The problem is, even if I add a 'view full site' button the redirect would be in place once the user gets to the full site.

I'm figuring the first step is to put the mobile version on a subdomain ... but...

Any thoughts?