So I plan on running Trackmaster (Trackaroo) on my Android phone coupled with a QStarz bluetooth GPS at TWS in a couple of weeks. There are a couple of cool updates to Trackmaster, since the last time I used it, that are pertinent to this discussion.
1. It now can use an external bluetooth GPS at 5 Hz. Before it could only do 1 Hz.
2. It can now export data in a format that is compatible with RaceChrono2AVI, which is a FREEWARE video overlay generator. http://www.racechrono.com/news/?p=92
So, if you already have an android, and get a qstarz bluetooth GPS (non logging ones are cheap), then there is an inexpensive option for logging data (Trackmaster is $5 IIRC) and doing video overlays (free).
Trackmaster is here
Not affiliated, blah blah. I have used trackmaster and it works. I have not tried the video overlay yet. I have an old camcorder that has firewire output, which is oldschoolz. I need to get a cheap HD solid-state video cam like all of the ones I have seen floating around.
EDIT: I have used racechrono (at MSR) and that works too. It was within 1/10th or better of what the NASA transponder printouts were indicating. I think the main source of error was the location of the start/finish line in racechrono versus where the AMB receiver was at.