I hope you find it of use.
The search page can be found at the Google Co-op site and searches the following sites:
- Google Gadgets for your Website
- serverboy.net software
- Sexy Widget
- Widgets Lab
- Widgetbox Blogosphere
- Your Minis
More examples of Google Search tools can be found here
This includes an example of the Widget Search embedded into a website page.
The Google Custom Search Blog provides tips, news and upadates.