All I was seeing was ton of xml based URLs like this:
http://www.blahgadget.com/gadget_gmail.xml
It took a bit of searching around to find that in order to actually use these URL gadgets there is quite a simple procedure:
- Simply open your Wave and edit a Blip.
- Click the green jigsaw puzzle shaped icon in the Wave edit tool bar:

- Paste the URL into the box that appears:
Be careful not overload your public Waves with gadgets though.
