I lied, I can do it today. 8*) It seems to make no difference to my setup (*) whether the APs are on separate channels or common channels, Ping Plotter will show a momentary interruption in service, but WinAmp will continue to play an MP3 file off my server (usually) without a glitch.
Since it makes sense that in a multi-user setup you'd want people to be able to use separate channels to reduce interference, you probably want to use the usual three non-overlapping channels: 1,6,11.
(*) Linksys WAP54G V1 (FW V2.07) and V2 (FW V2.08), Dell Latitude D600 with Intel 2200BG with 9.0.2.25 drivers, WinXP(pro) SP2 with all the latest patches. WPA-PSK/TKIP. Your milage _will_ vary.