I don't know if anyone else has ever considered these, but after a week of 600+ mile days last year, the soles of my feet were completely numb. The numbness continued for nearly 2 months after I returned home. I was poking around the internet, looking for rubber inserts or covers for the pegs, but all I could find were aftermarket pegs. BMW does not sell rubber for the pegs on my 2009 GSA. Someone on a forum pointed to the 2009 Xcountry and said that the rubber covers would fit the GSA. I checked the microfiche, but the 2 bikes do not share common footpegs. I spoke to the parts guy at MAX BMW and he had not heard that the parts were interchangeable either. I decided to risk the $50 and take a shot. I ordered the following parts from the 2009 Xcountry.
'46 71 7 696 748 Footrest rubber (x2)
'46 71 7 696 948 Retainer bracket (x2)
'07 11 9 902 745 Nylock nuts (x4)
The parts came in and they fit PERFECTLY. There are little grooves in the rubber that exactly fit the teeth on the pegs. The bolts line up perfectly and the retainer secures the rubber to the peg. Installation takes about 90 seconds with a 10mm socket. I can't imagine why BMW doesn't cross-reference this part to the GSA, but it fits as if it was designed specifically for this bike. Time will tell if they make any real difference, but it was worth $50 to me to find out.