This may interest some Ambit users - I saw something on DC Rainmaker's site about a desktop app for logging training / GPS tracks called Neotrack (google it). I asked the developer yesterday whether there were any plans to add support for importing the Ambit's xml file format, he asked me to send an example log file, which I did, and he added support within a day of my original email! I've not played with it much yet, but initial impressions are pretty good, and it allows you to export your Ambit logs to gpx and tcx formats. Provides a nice offline alternative to movescount. It seems to be importing the GPS altitude data from the logs rather than the barometric samples, I've asked him if it's possible to change this or make it an option when importing.
Note I have no affiliation with the developer or application.