I want to give our office manager access only to update our credit card information (i.e. https://manager.linode.com/account/creditcard). I don't want her to have access to the rest of the system (i.e. delete linodes, access the lish console, etc). Is that possible?

We're in sort of a deadly embrace here -- I don't trust them with the root password, and they don't trust me with the credit card number.

Account -> Users and Permissions -> Add a user, make them 'restricted' and then only give them the view invoices, make payments, update contact and billing info grant.

Hope that helps!
-Chris

Awesome, that's exactly what I was looking for.