The Bridge City Toolworks KM-1 is a clever instrument for perfectly sizing a dado, groove, half-laps, or anything, really, if you treat it as an instrument for perfectly calculating an offset. Visit the linked page for Bridge City's description of it, or, if you're not the type to "read it for the articles", watch the video of how it's used.
I'm currently making a simple cabinet for inside a closet. This will be a wonder of plywood case construction with plywood shelves dadoed into plywood sides. That said, I will be using the KM-1 liberally to ensure that I get exact dados for the "nominal 3/4" and "nominal 1/2" ply.
In the demonstration video, the KM-1 is registered against a stop block on a fence used while cross cutting to create the half-laps. Naturally you can do the same on a table saw crosscut fence, but what if you're using the rip fence as I will since these sides are 4-5' long by 22" deep? All you need is a stop block of sorts for the KM-1 to register against.
When I documented how I did a walnut inlay into cork flooring, I described how I used the KM-1 with the Festool OF-1400 router to make the inlay groove exactly match the inlay pieces. Basically all you ever need is a stop block of some kind. This MDF jig for the table saw will definitely make the KM-1 easier to use when dealing with the rip fence.