Yeah, the .224 subnet mask will do it. 224 is 11100000 in binary, leaving 5 bits for the subnet. 2^5 = 32, one IP lost to subnet number, one to broadcast, and you're left with 30 addresses.

In short, they don't need to match. Cisco's first CCNA book is 50% subnetting(or maybe just seems that way), and well worth reading if you do this kind of thing regularly.

I havn't bought a wrt54g in quite a while, I'm happy with my myriad of Buffalo's and am waiting for an open source firmware supported 802.11N router.

Matthew