In reply to hcawright:
Tenacious tape (or iron-on seam seal tape) is about 2cm wide, so stick one strip patch on the outside, and one strip patch on the inside, at right angles to each other. With a bit of luck, the overlap will stick, and, since the patches will stick to each other through the hole, should be fairly robust and secure. Certainly a cheap and easy repair.
Don't forget to round the corners of each of the strip patches, to stop them peeling.