PigeonHole is a free notes organization software that lets you easily organize your small notes. PigeonHole comes with a spreadsheet like interface. You type your notes in a cell, and whenever you hover over that cell, you see complete note description.
PigeonHole is not meant for long notes. Instead, it is meant for quick small notes, like post it notes.
PigeonHole has interface like a big excel sheet. To take notes, just start typing in any cell of the sheet. When you hover your mouse over that cell, PigeonHole will show you the complete note in a small pop-up window.
I really like PigeonHole for its simplicity. Sometimes there are lot of items that I want to jot down somewhere, but do not want to create separate notes for all of those. PigeonHole is ideal for those.