I used to run my Linksys WPA54G v2 AP with the HyperWAP 1.0 firmware (it original came with a v2.08 firmware) It was allowing me to decrease the signal so no one could catch my signal across the street. HyperWAP 1.0 was based on Linksys 2.07 firmware which is quite old.
Linksys released a 3.04 firmware a while ago. Some people released an HyperWAP based on this firmware, adding the few options HyperWAP was already giving and WPA2 security.
I now have WPA2 !! :)
Please read http://www.hyperwap.org/forum/viewtopic.php?id=53
Download : http://blog.wains.be/pub/linksys/wap54g_v3-3.04.02-hyperwap_V3.zip MD5 : 9ec257a3037816182317dbb0f47bf452
Use at your own risk, be careful about the compatibility with your hardware !