or the Kneeling RF/TFL stretch pictured on p. 53 of Maximum Strenth (Cressey)
The closest picture of I could find online is on page 13, figure 8 of the following: http://www.yorkbarbell.com/sh_summer2001.pdf
For stuff like that, I just bought a pair of athletic (nike volleyball) knee pads. Just put them on & no need to worry about carrying anything extra. Worked like a charm.
You can usually find these kneeling pads at the dollar store, in the gardening stuff:
__________________ The trick is in what one emphasizes. We either make ourselves miserable, or we make ourselves happy. The amount of work is the same. -- Carlos Castaneda