In The Raiser's Edge users have the ability to track what form a donor used for their contribution, using the Pay Method field. The field values are listed in a table which has been hard-coded into the database and cannot be changed. The allowed values are: Cash, Personal Check, Business Check, Credit Card, Direct Debit, Other. This solution lists several ways that additional pay methods can be tracked.
Add the pay method as a Gift subtype (The Raiser's Edge 7 only)