Several years ago, I wouldn't have been sitting at my Mac on a warm spring day. Instead, I would have been out cruising the hundreds of miles of Denver-area bike trails on my RANS V-Rex recumbent bike. During those rides, I kept track of my distance, average speed, and other statistics with a Garmin eTrex Summit GPS, but had no way to analyze my performance.
Since January of 2007, Montebello Software has shipped Ascent, an application that analyzes data from exercise computers. If that exercise computer has built-in GPS, the analysis includes a plot (static or animated) of exercise paths over satellite, topographic, or street maps.
Version 1.9.4 of Ascent now includes automatic syncing with Garmin Edge 605/705 cycling computers, drag and drop importing of .gpx, .tcx, or Polar .hrm files, and the ability to split or combine activities. I've been considering a Garmin Colorado for geocaching, and found that it syncs directly with Ascent. That may actually get me off my rear end and onto my bike again, since I can now do something with all of that ride data! Runners and hikers will also find Ascent to be useful.
A function-limited trial download is available, or you can purchase a full license for $40.