hagiograph

I just got an Inspector Geiger Counter that has a data-out port. It normally is used with "Observer" software from SEINTL but I was wondering if there are other data loggers that can pull in the data? I'd like to wander around various places (amatuer rock collector and I live in a very granite-rich area) and collect data on the radioactive content of some of the rocks around here but the INspector doesn't have any onboard data storage and I don't really want to lug the laptop along with it. Does anyone have one of these and any ideas on datalogging for it? Thanks