Just remember, if you format the USB drive, you won't just be deleting the Snow Leopard installer, but you will also lose your restore files for iLife.
Or buy one that looks similar to the MBA USB drive instead of losing your original MBA software:
Transcend and Freecom both make similar USB drives available in Black and white.
or just search for mba usb in ebay and buy one for $32 dollars, a little bit more expensive but they do look exactly like the onew that como from apple.