Are there any desktop or web-based applications that allow for meaningful analysis of GPS track data from perspective of cyclist/runner training use? It seems like everything I have come across so far is very basic display of track on a map and elevation profile (e.g. MapMyR..). I assume I am not alone in wanting to be able to use data for training purposes and :
- view speed over course of ride (summarized/averaged at different levels - by mile, etc.)
- compare performance on same track over multiple rides (ie. using data to understand where I was faster/slower on certain day)
- being able to store all tracks and use to easily summarize mileage trends, etc.

Ok, that's just a start for what I think would be useful and I'm guessing exists but haven't found yet. Reports generated at utrack.crempa.net are probably best have found so far but really is just fraction of what would hope for.

In case it helps I'm using MotionX's GPS app on iPhone and have been very impressed with app and with accuracy of track especially in countryside (much better experience than with some of the dedicated cycling/sport iphone apps).

Thank you for any suggestions.