On a Soekris board (4501 in my case), is there any advantage of using a
mini-PCI WLAN card over an external WLAN AP connected through one of the
ethernet port ?
It looks like to me that the external solution eliminates all the driver
problems and allows to use newer technology like 802.11a or g as well as
newer authentication methods. They're even cheaper for the 802.11b. On
the other hand, WEP key management may be easier to manage on m0n0wall.