Is it possible to update multiple contacts in a contact group upon submission?

Has anyone updated the contacts in a contact group with a some value captured on a form. The form does not captures the email address but some information and I need to update all the contacts in a contact group and send them an email.

I know there is no such form processing step that updates all the contacts in a contact group in a single submission but that would be very helpful in some cases.

Any ideas?

Thanks,

Shashank Sharma