I work as an executive assistant, and as such, I have very short completion cycles. If my bosses aren't around (they travel a lot) and I know I have some time, I'll just treat the 5 minute items as if they were 2 minute items and crank through them. Oftentimes it's the best way. If not, I have a "TODAY" folder, and at the end of every day if there's anything left in it, then it goes in my usual "ACTION SUPPORT" tray and gets inputted on my next action lists.
Hope that helps!