Looks like RaceChrono is the ticket. Found this review here (
Racechrono datalogger review - Technical Forum ) which was very helpful.
DL'ed their new Android 2.0 version and tested my 'lap time' walking the dogs tonight. Seemed to work great. I identified that the cause for my slowest lap were when I 'off course' for pooper scooper duty.
Will pick up a 5ghz external GPS and try this out at the next AX. Thanks again everyone for your advice. Hooray for more toys!