Our company operates a limousines service (www.sunsetlimousines.com). We recently rolled out online reservations. We use non inventory items (for example, JFK sedan service) with transaction item options (for pick up date, time, destination, etc.).

This is currently working great and we are now moving to put in our customers enhancements requests.

The most common request is to be able to store multiple addresses (for example Mr. Smith's home address, work address, gym, etc.) for each customer AND let them pick/change/add to these on the fly while entering the transaction. Toward this end, I created a custom record called My Locations and attached it to a new transaction item option field.