Do you allready use/have the radioshark? Does it work in a car?
How about GPS use for registrating business or private trips. Simply by pushing a private/business and start/stop button. Then it should record the date/time/distance (travellog) and should be able to export is to an excel compatible file (with your AstraMac Companion).
How about using it for calling and receiving in combination with a Bluetooth phone ans addressbook. (mayeby with BluePhoneElite) There will be a possibility in OS 10.4 for speaking and listening phone calls through your Mac. This would make a great handsfree kit.