I put together a script from a variety of sources including some customisations which displays the following information in the form:
External : x.x.x.x
Ethernet : INACTIVE
SSL : x.x.x.x
AirPort : x.x.x.x SSID: name Channel: 4
The External entry uses http://checkip.dyndns.org/ to get the current external IP address. Ethernet give you your local wired ipv4 address. SSL displays the current Juniper Network Connect assigned IP address. Airport shows the currently connected wireless network (SSID) and the associated channel.
It should detect if any of the connections are inactive. It has been tested on a Macbook Pro (17inch) Mac OS X 10.6.4. This may well be affected by updates to the OS as it is expecting specific output. You can drop the script text directly into the Geektool script editor.
I also made an executable version of the script so it can be called from a normal terminal.