adsl --------+  (plugged into wan, wrt gets dhcp from adsl)
x.x.x.x      |
             |
             |
                       (client mode)
PC1 --------- wrt54g  ((((((((((((((((((((((((( belkin AP    ))))))))))) PC2 (wireless)
192.168.3.2   lan:  192.168.3.1 (stat)          192.168.2.1 (stat)       192.168.2.x (dhcp)
(dhcp)        wifi: 192.168.2.2 (stat)                                   gw: 192.168.2.2
              wan: x.x.x.x

wrt54g runs DHCP server for two networks:
PC1 on LAN
PC2 on the WLAN (which wrt54g is a wireless client of)