Tracker, I just bought a Lowepro neoprene memory card case (DMC-H, same as what ckiang posted) from CP at Peninsula for $8. If you go to the Marina branch today they should have it as well.
I tend to keep the cards in the plastic cases, and find that 4 will not fit into the neoprene case ... I think their capacity of 8 is for small sized cards (SD, SM) without case, as there are only 4 pockets.
Therefore I can only keep 2 CF cards in mine ... which is fine, as one of the cards is an MD and I like the idea of the neoprene absorbing any shocks to the card.
My advice is to bring your cards along with you to test out ... shops will likely not be able to lend you any cards to do this (as the new cards will be in their packaging).