You could get a US postal money order with the card and send it to BitcoinMorpheus aka Matthew Courtney who was very professional and a pleasure to work with when I sent my money order. Then he'll give you credit for Mt. Gox.
He gave me Dwolla credit instead that I could then proceed to use on TradeHill, but that may have been a one-time deal, since I sent my money order prior to the Gox shutdown, and then it shut down before he had given me my credit, so he offered to give me the held funds in a different way.
You could send him an email asking if Dwolla is possible, you might want to make it short and to the point though since I'm sure he's being flooded with email right now and from what I can tell it's a one-man operation.
Alternatively you could just get Mt. Gox credit, which you may be more averse to because of the whole database fiasco, but I personally am just going to trust them more now that they've ramped up security in response to it.
Just remember never to keep all your eggs in one basket. Something you can do for free and with virtually no credentials needed is create a Dwolla account. It'll say stuff about verifying with a bank account, but this is only necessary if you want to transfer funds to a bank account or vice versa, you can transfer funds from the trading sites easily.
Even if you don't trust Mt. Gox, TradeHill could easily have the same thing happen to it at any time. Whichever service you use, keep some of your USD funds in Dwolla and some of your bitcoin funds in your wallet.
I do however advise trying a little harder to get the card sold, as it'd probably be easier than everything I said above.