Google can be coaxed into adding radio buttons for site searches, like in this example of a web search about cookies :-

http://www.google.com/search?&domains=iMilly.com&q=cookies

Look under the search box, and you'll see a radio button to trigger a search for cookies on my site.

Of course you can change that to any site you wish, and add others.

To be more useful, you might incorporate such an animal as your main Google bookmark, or within the built-in searches in Firefox, Opera, etc, or as a Bookmarklet.

Or you could write yourself a (non-functional) note: such as a caution :-

http://www.google.com/search?&domains=Surf Safely!!&q=+

Or a reminder about Google's operators and alternate query types (you can't click them directly, but you might copy'n'paste them into the search box, or just have them there to jog your memory about what is possible) :-

http://www.google.com/search?&domains=cache: date: define: info: link: related: site: stocks: allinurl: inurl: allintitle: intitle:&q=+

Here's how, with some other examples :-

http://www.imilly.com/bm.htm#Google_Tricks

I hope these might be of some interest to some :)