After reading on lifehacker that google have added some new search options to refine your searches I had a brain wave. One of the new features is to narrow your search by “Visited Pages” and “Not yet visited”. If you spend alot of time searching through the serps for possible websites to request a link from, narrowing your search down to “Not yet visited” will be a great help as it will only show you websites you have never visited before (and presumably already requested a link from).
Please note to get these new search options, you need to be logged into a gmail account.

Thats actually an awesome idea. Will be using that for my link building campaign.
Another point from that screenshot – the Wonderwheel is a very cool gizmo that shows words that are seen as similar to the search query. Find out more on Phrase Based Indexing & Retrieval at http://www.huomah.com/Search-Engines/Learn-SEO/Chocolate-and-PaIRs-and-Jaguars-Oh-My.html
Excellent idea. Thinking of new linkbuilding strategies are harder and harder to come by with blogs and articles coming out each day. Congrats on your ingenuity.