No, I'm talking about a xgauge feature they call GPS which tells you your gas pedal position (since its drive by wire). Supposedly you park your GPS at 16.5 and you should hit SHM pretty easy. I got this info from DiamondLarry who is knocking out some insane mileage numbers (mostly from avoiding the highway though). He said he has knocked out 70+ mpg highway segments with pulse and SHM for glides.
I just got off the phone with linear logic and they said that they can update the scangauge to a different version that would probably work, but no guarantees. Ack, a week or two without the scangauge, what will I do?!?
For a very nice list of scangauge xgauge options for the Prius (most are useless though), try this link.
CleanMPG Files - Prius xgauges