Profile dropdown choice puts you in certain usergroup

[RollaJedi]

Hello

I am wondering if something like this exists: I have a star wars sight for fans. Something quirky and fun I thought about adding was the ability for the new user to be able to pick which alignment he is. I would do this in a drop down probably and the choices would be 'the light side' and 'the dark side'. Depending on which they chose, I was hoping that I could get vbulletin to automatically put them in a usergroup I have created. One usergroup is called 'the light side' and one is called 'the dark side'.

Each usergroup would have its own 'abilities' like darker, more evil ranks for the 'dark side' usergroup members to have, for instance.

Can something like this be accomplished perhaps?

Thank you!