This is not exactly news, but Google offers a nice tool for creating custom search engines that allows you to search within a particular domain. But they also have a quicker, simpler tool that allows you to create a domain specific custom search engine on the fly.
I tested this out using our domain (see the screenshot to the left). Once I had my search engine created (this took a few seconds for Google to process), I searched for 'prototyping' to see everything that we had to say on the subject. You can see a small screenshot of the search results page below, or click to view it here. They do inlcude sponsored links that may not correspond to the domain you've isolated. However, the tool is overall pretty useful, especially for content rich sites like ours.