I’m the happy owner of a nice geeky toy: a Suunto X6HR watch, that includes an altimeter and an heart rate monitor, which I use mainly for moutain biking and hiking.
During outings, the watch can log the altitude and heart rate every 2, 10 or 60 seconds, and the data can be transfered to a PC using a serial interface. The problem is that Suunto only provides software for Windows. I got tired of using virtualbox to connect to the watch (qemu doesn’t work, Suunto Activity Manager apparently does strange things with the serial port), so I reverse-engineered the protocol (using skimanager and Jérome Kieffer’s work as a basis) and implemented a script to fetch the logs, and export them in a format suitable for gnuplot.
Of course, Suuntux is publicly available. I’d be happy to hear from you if it works for you too. Also, if you own a Suunto X6 (similar watch, without HRM), I’d be interested in supporting it too (if it’s not supported already).
Below is a example graph, from a short mountain bike ride just before leaving for Debconf.