In the past I used ARKeys, but it wasn't exactly what I wanted. Instead, I built my own interface using AutoHotkey, which I also use to make Foobar2000 car-friendly.
And next to this, the requirements of S&T keys rule it out for use on my Asus R2H:
- screen vertical resolution of minimum 600 pixels
R2H is 800x480
- fast computer, Typical pentium IV, 1.7 GHz
R2H has a Celeron 900MHz
- Microsoft Streets and Trips 2010 version
I use AutoRoute (2007 at the moment)