I’ve had a couple of people ask about how I get my mountain bike rides listed in the sidebar here. This blog is run on Movable Type, and the sidebar is created by an MT feature called Action Streams. Action Streams are essentially feeds from other sites which are aggregated together on an MT site by a plugin.
The Action Streams plugin itself can be extended by other plugins, usually to add more external sites and services to poll for content. I created one for Garmin Connect, which can be found on my GitHub account or on its page on the Movable Type plugin directory.
It was easy to write, but hopefully this saves someone a little time.