Those white drawers on the left by the lamp are exclusively for sticky notes. Flags go in the top drawer, small rectangular notes in the middle, and regular 3"x3" notes and specialty notes (stars, footballs, etc.) on the bottom.
I use sticky notes for everything: edits on documents that I don't want to mark up, to-do lists, makeshift index tabs, directions, addresses on shipments (for ops staff to send), cleaning my keyboard (sticky side down). Although my home supply is typically the smaller stuff, at work I also like the lined kind (about 4"x6") or even the large wall-posted sized ones for meetings and brainstorms. Adhesive + paper = endless possibilities.
Sticky notes were (not so intentionally) invented in 1968 when 3M chemist Dr. Spencer Silver developed a pressure-sensitive, reusable adhesive. Initially, 3M struggled to find a use for this new discovery, and it wasn't until 1974 that Art Fry, one of Silver's colleagues at 3M, came up with the idea of using the adhesive on strips of paper to use as a bookmark in his church hymnal. In 1978, Fry began marketing the product under the brand Press n' Peel, but the sales were disappointing. Post-its were officially introduced into the U.S. market in 1980. Post-it flags came soon after in 1987. The patent for Post-its expired in the 1990s, opening the door for other manufacturers to get in on the sticky note market.
In case you're curious, 3M has a fun timeline of fun facts about their Post-it product on their website.
Marking notes and comments
Sticking reminders or inspirations quotes in high visibility places
Makeshift lint roller
Label things temporarily
Fun with sticky notes
What are your favorite uses for sticky notes?