Investing $10k to get a good return is one of the toughest amounts to deal with, in my opinion. It's too much to do the easy and obvious stuff (pay off a $1k credit card which you've probably already done long ago) but too little to do something big with that won't tie it up forever to assure a decent return (buy a house, get some mutual funds).
I've come to think that there's an easy way to get a good return over a relatively short period of time that's also a controlled risk. Sounds like you rent so offer to pay your landlord a year's worth of rent in advance in exchange for one month free. What you earn on your money is 8.33% (1/12) and is something you'd have to pay anyways. MAKE SURE that you continue to pay your rent each month but pay it to yourself instead (otherwise, you are stealing from yourself). As a landlord, I am surprised that no tenant has tried this offer on me. Personally, I wouldn't take an 8% reduction on my gross rent but I would take 4-5% if I had a project in mind where I needed some cheap financing. But I could definitely see some who would accept this offer. I'm sure many will reply that you need all of this money in the safest possible reserve account. But the reality is that if you actually want to earn something on your money, it requires taking on more risk and this is a relatively low-risk way to do that. In addition, it's not that you'll suddenly be completely vulnerable financially. Your financial cushion will simply be transformed from static savings to high positive cash flow, i.e. you will have money available each month that is far in excess of your liabilities.
A couple notes of caution however: