Ah, found it (only $599.99?!)
http://www.xtremeflow.com/hummer.htm
Power Programmer
The ProFlash is a powerful tuning tool that allows you to set the level of tuning that you want. This is done using separate engine and transmission files for your Hummer, allowing you to change to the mode that you want to run. The octane level and ping control can adjust for fuel quality in different areas of the country and different altitudes. The ProFlash can also correct for altered tire size and for ring and pinion changes. The speed limiter can be set to stock, 130 MPH, and unlimited.
The ProFlash will adjust the following items on your H2 Hummer
correct speedometer for changes in tire height and rear axle ratio
reduces or removes torque management on H2 Hummer
Engine tuning (economy, towing, performance)
Shift Firmness (economy, towing, performance)
Shift points (economy, towing, performance)
Ping control (Sets timing +/- 5%)
Octane level (87, 89, 92)
Speed limiter
Tire Height
2003 Orange H2, Viper Responder Alarm, Audiobahn Sound, 325/65R20 M/T tires on order from Toyo, 20" Monsta Wheels, Rosen Video