I'm suprised noone has pointed out this mod bares a striking similarity to the suit function menu of Crysis. To explain briefly for those who haven't played this game yet, your battlesuit has 4 different modes of operation you can change on the fly in combat: stealth, armor, strength, speed. It's very intuitive after only a couple minutes of use, and it works EXACTLY like this mod (without customization, of course).
Organizing your items in a ring is a bit confusing, and doesn't update immediately. You have to OK the options menu to see your changes on your ring. This is not a big deal, something I'm sure the author can fix at any time. One of the best features IMO is the ability to write macros within the mod. My paladin's personal macros were filled before this, now I have a click for 10 min buffs, a Ctrl-click for greater blessings, and a half-empty macro page
I recommend checking this mod out if you have 60 castbar buttons on your UI, like I did.