With the ever-changing kaleidoscope of colours, brands and formulas we're presented with, there must be literally millions of bottles of unwanted and forgotten polishes gathering dust in beauty cabinets around the world. How distressing!
One solution that might be fun is to have nail polish swap parties, along the lines of those clothing swaps that were all the rage for a while there. You bring along the six veeeery similar OPI reds you have somehow accumulated, and that taupe Chanel shade you thought would look edgy but actually makes your hands look like a dead persons, and swap them for six new pastel OPIs and a classic Chanel pink. How's that for problem solving!
The other very cool solution comes via Honestly...WTF, and that is to re-purpose your polish. Usually I steer well clear of anything remotely crafty or homemade (by me, that is), but this actually looks do-able, and I really like the results.