No, there's no WLAN switch on the computer. The only switch turns the power on or off.
Could it be that Ubuntu 10.10 doesn't recognise my wireless dongle? It's a Belkin, but I don't have much more info than that*. I've just run a system test which detected the following controllers:
Broadcom Corporation BCM4311 802.11b/g WLAN (rev 01)
Broadcom Corporation BCM4401-B0 100Base-TX (rev 02)
*Edit: It's a Belkin F6D4050 v1 which has a MAC code and SN number.