As for the case for S330: I checked PowerShoot.com and Canon has PSC-300 case for S300 and S330, because
they are of the same size. You can also get a waterproof one, but I think it is too expensive and an overdo.
Buy.com has PSC-300 for $7.96 + $5.02(S&H) = $13 (You may get free shipping for order $99+)
Amazon has PSC-300 for 11.99, (You may get free shipping for order $99+)
I will also buy Yamaha TSS-1 for 125.88 at amazon.com so I can use free shipping, together with $10 off coupon.
Just my 2 cents.
Edit: Oh, NO! TSS-1 goes up to $149.88 for now. But buy.com still has it for $173.95. I will use amazon anyway.