Words of wisdom, sort of:
There are no missing objects. Only unsystematic searchers.Findologist Professor Solomon has made his How to Find Lost Objects available as a free .pdf.
I've heard of Professor Solomon's 18-inch rule (objects "tend to travel no more than eighteen inches from their original location") and have found it genuinely useful when looking for things like keys, Moleskines, pens, and wallets.
How to Find Lost Objects (.pdf, 5.2 MB) (via Quo Vadis Blog)