i picked up a pair of these recently http://www.chainreactioncycles.com/Models.aspx?ModelID=3539 as a “better safe than sorry” measure (i had the epiphany whilst lying in the gutter one night having slipped off the kerb staggering home from the pub. was doing pretty much this for a couple of minutes:)
[video]http://www.youtube.com/watch?v=sHbPgDvAvf0[/video]
haven’t used them as much as i should – it’s going to be a while getting used to the feeling of a knee covering, and they’re quite bulky & warm. cheap and cheerful though, and seem pretty strong. i got a small (5 7″ and a scrawny runt) and that fits fine with room to grow in case i ever turn into a real man.