I have been umming and ahhing over which which drive(s) to get over the past few days. After doing some research on the forums of the manufacturers of the drives I was considering, I've decided to get 2x16gb Corsair Voyager GTs.
I have a 4gb drive of the same model, and it performs like the benchmark above, approaching the very limit of bandwidth provided by USB 2. Also worked out over £10 cheaper than a single high performing 32gb drive.