You’ve probably got an old floppy drive edge connector or two lying around from an old computer. You can save a bit of money and recycle these as SD/MMC card sockets for your electronics projects. The card can then be used in MMC mode by just wiring up a few I/O pins.
Rob Wentworth documented using this faux-sd floppy connector to add SD support to his WRT54G router. If you’re using the DDWRT or OpenWRT firmware for your Linksys, this hack can give you a huge upgrade with more data storage space and swap ram.