I have set my WEP configuration according to the FAQ:

# nvram set wl0_wep=on
nvram set wl0_wep_bit=128
nvram set wl00_key1=DEADBEEF12345DEADBEEF12345

After restarting the interface, iwlist shows the key set up:

# iwlist eth1 key
eth1        4 key sizes : 40, 104, 256, 128bits
            4 keys available :
                  [1]: DEAD-BEEF-1234-5DEA-DBEE-F123-45 (104 bits)
                  ...
            Current Transmit Key: [1]
            Security mode:restricted

...But if I'm not mistaken, the key that is put in is a Hex key. I need whatever the passphrase, or key, or password or whatever to put into my clients (don't I?)  I have WinXP and Apple OSX clients and can't seem to get them to connect.

TIA

DS

Not sure on the WinXP but OSX doesn't use a standard hashing algorithm.  Even if you use exactly 5 or 13 chars for WEP (64 vs 128) thus generally avoiding the "filler character" problem it still won't work. 
   The only way you can get OSX to connect to a third party router using WEP is to manually enter the raw hex key.  Some versions of the AirPort tools don't have that option but you can work around those by prepending a dollar-sign at the beginning of the key (undocumented feature I guess).
   Note that in a few cases, due to some strange UI bug, I've had to enter the key first, then go back to the beginning and insert the "$".
   Good luck!