To create a custom search button, follow these steps:
- Visit a website with a search box, like Wikipedia.
- Right-click the search box.
- Choose Generate Custom Search.
To search Wikipedia, enter a search query into the Google Toolbar search box. Instead of clicking Search or pressing Enter, click your new custom search button to search Wikipedia.
You can use this tips on most websites with search boxes, but there are some that still aren't compatible with Google Toolbar. You can let me know about specific problem websites by posting a comment below.