It sounds like something that could most usefully belong in an OSM editor rather than a post-processor such as GPSBabel, but I'm not aware of an OSM editor that can do this. In addition to "subtract elevation on start of segment from elevation from end" you'd need to manually indicate the start and end of a particular incline. I have a Garmin eTrex Vista HCx (which also has a barometric altimeter, and all "trkpt" trackpoints have an "ele" tag that contains the measured elevation, so the data's availble (have a look at [my traces][1] to compare with yours if you want to see if the data is in the same format - you'll need to find a text editor that can understand xml better than e.g. Windows Notepad, of course). Of the OSM editors available, JOSM is the most likely support this. It does support [plugins][2] and it's possible that someone may be working on something similar, or may in the future work on something. do so. [1]: http://www.openstreetmap.org/user/SomeoneElse/traces [2]: http://josm.openstreetmap.de/wiki/Plugins

It sounds something that could most usefully belong in an OSM editor rather than a post-processor such as GPSBabel, but I'm not aware of an OSM editor that can do this. In addition to "subtract elevation on start of segment from elevation from end" you'd need to manually indicate the start and end of a particular incline. I have a Garmin eTrex Vista HCx (which also has a barometric altimeter, and all "trkpt" trackpoints have an "ele" tag that contains the measured elevation, so the data's availble (have a look at [my traces][1] to compare with yours if you want to see if the data is in the same format - you'll need to find a text editor that can understand xml better than e.g. Windows Notepad, of course). Of the OSM editors available, JOSM is the most likely support this. It does support [plugins][2] and it's possible that someone may be working on something or may in the future work on something. [1]: http://www.openstreetmap.org/user/SomeoneElse/traces [2]: http://josm.openstreetmap.de/wiki/Plugins