http://www.triboseat.com/rider.htm
Bought one of these last week as my one-piece leathers seem to have a very slippery rear end. Works a treat and not very expensive either.
No more painful 'balls to tank interfaces now'!
It does ..but you have to remember to use it and grip firmly with the knees and thighs!
This just adds a bit more so i don't move around the seat unless I want to!