I have a few that are expiring also - I might just cancel my credit card (although, I think as soon as you cancel the card - the voucher disappear)
... of note, I have tried to give away stuff like that - drink coupon, business first upgrades, etc - but I have been told a few times that active duty are not allowed to accept "gifts"

not sure what I am going to do with mine - I might have a few flights coming up - but dont expect hanging around the airports long enough to use them - but is not using them better than wasting them by going into the lounge for an hour?