That's really too bad. I don't have a MacBook Air, but those things are so sexy as USB drives. It's so sad that you can't repurpose it.
You can easily image any Snow Leopard DVD/restore image onto any >8GB USB drive to make a restore disc. I keep an install DVD imaged on my 8GB stick just because it's at least 5 times faster than installing off the DVD itself.
Unfortunately, there is only one way to get one of these as a USB drive.