I live by the motto: "A place for everything, and everything in its place." I don't search for keys, because they always go in the drawer in the entrance hall when I walk in, and in the same place on me when I walk out.

Electronically I'm the same with clutter as you are. An inbox full of email stresses me out massively. My goal (90+% successful) is to leave each day with 7 or fewer emails in my inbox, 11 or fewer drafts to be finished, and 11 or fewer sent items to be revisited or archived. Hard numbers make it easy to know when I'm "done" (or have done enough) for the day. It is 10:59 here and I'm at 5/10/10 - that bit of reserve is soothing, like mentally hiking a deserted mountain path.