A fantastic feature of the physical rolodex is that one needs to simply place the business card in the rolodex to "create" a contact.

Since email is a dominant form of communication and source of new contacts, does anyone know of a simple way to parse the email signature to create a contact?

(Personally, I don't care if the virtual rolodex is 37Signals Highrise, Apple AddressBook, or Gmail Contacts because I'd be willing to switch if I could create/sync contacts with a "click".)