Ask HN: What should I be doing with our business' cash?

Using a throwaway account, since we are semi well known. We are a mature, cash flow positive and bootstrapped company that is sitting on a business checking account with $280k in it. $100k is earmarked for 2015 taxes with a known due date. The rest is just general operating funds, about 3 months of run. What should we be doing with this cash that we can't necessarily spend, but don't want to have sit idle making no money for us? Are there any good options that beat the measly < 1% rate a CD would get?