Does there exist a tool that will monitor eBay for new auctions with certain keywords?

Yes.

It is built right into ebay's software.

Do a search with whatever keywords and parameters you want (i.e., "empeg"). At the bottom left of the page of auctions that the search generates in quite small print is the link "Save this search". This will add that exact search to your "My Favorite Searches" tab in the "My Ebay" page that you have as a registered ebayer.

Go to that Favorite Search item, and check the box that says "Email Me" and click the submit button. From then on, any time an auction has the word "empeg" in it, you will receive an email within a few hours of the beginning of the auction.

It is easier to do than these instructions make it sound.

tanstaafl.

Well... that'll teach me to type faster. Looks like about four people beat me to it!