Some reasonably cheap camera / video cases at this shop.
The case for the IXUS i seems cheap at £2.29 + £2.93 postage = £5.22 delivered.
There are also some other cases with batteries included - packs are:
PVK103 kit - (Soft case & NB2L Battery) for £9.99+P&P
PVK101 kit - (Soft Case + BP-508 Battery) for £9.99 +P&P
These prices aren't too bad for genuine Canon camera batteries on their own.