We just went through one monster thread on this. To save you all the gory details, here is one way, albeit not all that cheap:
Get two more Wap11s. Place them at some point where they can still receive the signal of the original WAP11.
Configure one Wap11 in client mode. Set it to the same SSID and channel of the original WAP11.
Crossover-Cable-connect another WAP11 (leave it in the default access point mode) to the WAP11 in client mode. Set it to a different channel and different SSID than the other 2 WAP11s.
So, faraway WAP Access Point sends signal to WAP in client mode. Client mode WAP gives the signal to the cable-connected WAP which then continues beaming it using a different ssid.
Reason for different channels and different SSIDs is to prevent conflicts -- otherwise WAP in client mode would pick up the signal of the WAP right next to it and miss the signal of the faraway WAP.
Whehter this is better or cheaper than other mehtods, I don't know, but people who have tried it say it works.
Also, WAP11 client could be replaced by Linksys WET11. Also, you could connect a switch to the WAP11 client if that would fit your needs better.
Incidentally, official Linksys approved method uses 4 WAP11s, two configured as point to point brdiges and two as access points. Main advantages seem to be (a) you can use the same SSID throughout (b) Linksys sells more WAP11s.