[QUOTE=markhr;7613483]In the UK the most common reflective back pack covers are the stuff sold by Respro. They have the advantage of being able to use any suitably sized backpack rather than buying a new bag.

http://www.respro.com/
http://www.respro.com/products/urban...ty/hiviz_hump/




I did see the various backpack covers, but eliminated them because my commute is a mix of bike and train, and I don't want to be fumbling with a cover. And, I do want to preserve my old backpack for other purposes, so I do in fact want another backpack. And, this one's relatively cheap - US$30 or so. And my bike is a Trek 7300 hybrid, with a fairly upright riding position, so this works for me.

The idea of reflective tape on the butt of my overpants does have some merit, though!