How do I get wireless working from the Debian shell?

Here is what worked for me on a C700:

  cru cardctl scheme CardResume
  cru cardclt scheme qpewlanX  # X is a number of 0 or more and corresponds to the numer of the WLAN connection defined in the ["QTopia"] Network GUI

This should fire up the network connection and the wlan card tries to get an IP-Address from the DHCP server. If the LED keeps blinking, the scheme data is not correct or the server doesn't answer. You can then turn the network off and on with these commands:

  cru ifconfig eth0 down
  cru ifconfig eth0 up

To shut down the wireless connection, do the following:

  cru cardctl scheme CardSuspend