Ok, we should all know by now they dissapear after 24 hours, right?
Well, here's what I did.
After reading the post about being able to send them to twinks, I sent 100 of these to my 19 hunter. I logged on him about 2 days after and they still had 24 hours left on them.. So I thought, if I mail these to my bank alt, open in 28-29 days, mail back to main and repeat that once a month, by the time it gets to around Feburary these could actually sell for quite a bit of money to some twinks / PVPers.