I found plans just like Joseph's from Fine Woodworking on the net once and built one. It worked reasonably well. However, since then I bought an Ibox jig which is far more versatile. With the jig like I built you must have the same thickness dado stack each time you use it and with the Ibox jig you can put any size stack on and then set the jig to it. Of course if you are using a router instead the bit will stay relatively the same size so that won't be an issue.
By the way, before I took the home made jig apart I used it to make some dentil molding with it. If you look through my uploads you'll find it and the thread that went with the pics.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.