For about that last month or so, I've been testing a new system for disc grinders. It consists of a "hub" that attaches to a 5/8" motor shaft, and it has interchangeable "face plates".
This is about the best tool that I've seen come down the pike in a long time! It allows you to change "discs" on your Disc Grinder in a matter of seconds, saves a ton of time, as well as keeps you from having to waste sandpaper every time you want/need to change grits.
There's far too much information about it to include in a forum thread, so I built a quick web page. You can see it here:
Disc Grinder with Interchangeable Face Plates
I don't give recommendations for tools often, or lightly. This thing has saved me a ton of time and kept me from wasting lots of sandpaper! I'm not getting anything out of this, just wanted to share a great time and money saving tool with everyone.
The gentleman who invented/produces this system (Rod Nielsen) has worked really hard to ensure that everything about it is right, and I think he's done a great job. For what you get it's reasonably priced too!