Zyxel to offer up to six bridged connections: It's a small but growing story that the wireless distribution system (WDS) is starting to appear in a number of consumer/small-business access points. WDS allows you to use multiple APs on a single channel to bridge network traffic to a master unit.
Of course, the problem is that you massively reduce available bandwidth in your wireless pool by sharing the same channel, but you also reduce your wiring costs and make bridged networks possible where before you'd have to buy either very expensive equipment, a set of Linksys devices, or make lots of compromises.
Apple's AirPort Extreme Base Station support up to four slaves pointing to a master in a point-to-multipoint configuration, but I haven't tested their version of WDS with other vendors.