What I would do RIGHT NOW...
Print out every page of your site making sure that all of the pages have the date on them. I would also put a copy of the website on disk. Use the original FrontPage or Dreamweaver (or whatever editor you used) files which have the "created on" time stamped to the file. Then, I would take all of those and put them in an envelope with your address as both the return and "ship to" address. NEVER OPEN THE PACKAGE one it is delivered to you. Simply put it away for that rainy day when you might have to go to court. It may help to prove you were the first to create and go live with that exact site. At any rate, it is just a good thing to do. Postage won;t cost you much, however, that depends on how many pages you've got.
I would also copy his pages spo that you can prove he was using your footer with the copyright info.
As well, I think it would be a good thing to make copies of those other sites he has stolen.
Anyway...
I would send him a letter in the mail if his whois info is not private. If it is private then you might be able to get the address from the company that offers the privacy service to this person. In your letter, be brief, forceful, and to the point. Almost as if you are a lawyer sending a Cease & Desist letter.
I would also report him to his host like others have mentioned making sure that they understand that when the lawsuit is filed, the too will be sued as the content is residing on their servers. this should get them to act in your favor quicker, but do not come accross as rude as they may take offense and (if they are a big company) may not even listen to you pleas/demands.
38 domains found on 72.9.237.81
That means nothing. All hosting packages that you see advertised everywhere that are affordable to the common man is SHARED hosting. You share your server with others, Therefore, you all have the same IP address unless you request a dedicated IP (which you would need of you wanted an SSL cetificate for your site) or pay for dedicated hosting which means you have your own server and therefore no one will have the same IP address as your site.
If all of the suggestions in this thread fail to produce the desired results, you will need to get a lawyer to send him an official Cease & Desist letter and if that does not work (but it probably will) then you have to file suit against him.
Like others have said, you should report him to his host, ICANN, and his domain reg for using false whois info (if in fact this is the case). If it is true he is using false info on his whois, I would report him regardless if he takes his content down today or not. Why give this guy any slack, he is a slimebucket and looking to profit off of your hard work!!!
Good luck.
Fundraiser, than you for the link to that site. That is a wonderful tool even if it is not 100%.