I'm interested in the answers. I have basically one year's salary sitting in an ING mm account because I freelance and my clients can sometimes take a while to pay me. So far, I haven't had to dip into the fund at all this year, so I should probably just move it somewhere better than a MM account.
Money Market Would be the easiest option, although some of those do have fees if your balance dips below a certain amount. Short term CD's might be another option. They earn interest and can have as little as 30 day terms.
I would put it in an ING account - takes a few days to get the money so safe from impulse dipping into the account. (You really would not spend your son's tuition - right?_ No one is paying anything for interest - there are no high interest accounts with the Prime rate at near Zero. I would stay away from the stock market as you risk losing your principal. Keep it safe and keep your hands off of it!