I think I got one of those last weekend while trying to photograph the Perseids.IMAGE LINK: http://cisp.zenfolio.com/img/s9/v90/p2466089766-4.jpg
I had my camera on timer, doing 20 second exposures w/ 2 seconds in between (my timer isn't very reliable). When I looked back at the photos, i thought I had a good meteor, but then I noticed subsequent photos had a continuation of the streak. I merged the 5 or 6 shots (so 100-120 seconds total) where the streak was visible. My only guess was that it was an iridium flare.