Today’s post comes from Miranda Marquit. She writes about personal finances for YieldingWealth and edits debt consolidation information for Destroy Debt.

The “economic stimulus” tax rebates have begun arriving, and now people are wondering how to spend them. Instead of blowing all that cash on something you don’t actually need, why not put part — or even all — of that money to work for you through investing? Here are 4 investing ideas for your “economic stimulus” tax rebate check:

1. Retirement account – If you aren’t putting the maximum amount into your retirement account, why not use that tax rebate check to bring it up to scratch? Even with a modest rate of return (around 7 percent) over 20 or so years, you can make a big difference in the end result if you put the money in your retirement account.
2. Index funds – In general, the stock market is struggling a bit. This means that now is an ideal time to get in (you know, the old “buy low, sell high”). You can buy more units for your money. And if you choose index funds, you can enjoy instant diversification. Over time, the stock market gains. You can take advantage of that buy getting in now, even though the returns are modest, averaging between 7 and 11 percent.
3. Cash – This is not going to get you a great return right now. But cash investments (like a high yield savings account or a CD) can be a good way to build your emergency fund. And they are safe, if you use a bank that is FDIC insured. You can pad your “rainy day” fund with an infusion in the form of your tax rebate check. The money will grow (albeit slowly), and offer you a bit of a safety net. Besides, the Fed has to start raising rates again sometime. When that happens your savings account yield will increase, and you can ladder CDs into something with a better return.
4. Growth stocks – If you’re the type of person who can stomach a little more risk, this might be a good opportunity for you invest in some growth stocks. These stocks are riskier, and you could end up losing the money, but it you choose carefully, you just might parlay your tax rebate check into some serious stimulus for your investment portfolio. One of the more promising sectors is clean tech.

What you choose to do depends on your risk tolerance and your investing style — as well as your individual needs. But no matter your decision, you can put this “found” money to work.