$25 Sign-Up Bonus at Prosper.com

Perhaps the 5% return you're making in your high-yield savings account (See "Is Your Bank Robbing You?") is a wee bit too conservative for your taste. You'd prefer to try something a bit more aggressive for a chance at higher returns.

But let's say you don't want to tie your money up in a good long-term investment like a 401K or Roth IRA, since you might be working with a shorter time horizon before you need the money for something like a new car or a downpayment on a house.

You could lock your money up in CDs. Or you could throw it into the stock market and hope for the best. There are, of course, many, many options.

One option you might want to consider is Prosper.com. Here you can lend your money in $50 increments to borrowers for potential annual returns of anywhere from 8% to 12% to 15% to 18% -- you get to pick. Of course, there is some risk that the borrower won't pay you back. But if that happens, rest assured that Prosper at least will send a collection agency after them.

Christina and I have made quite a few loans on Prosper and so far have been very pleased with the way the web site works. Since the loans are 3 years in length, we won't know for some time what our final return will be, but we have a pretty good sense that we'll be doing much better than 5%.

If this sounds like something you'd be interested in, now might be a good time to check it out. Prosper is currently offering a $25 sign-up bonus for first-time lenders who register and fund a loan within 90 days.

The minimum bid to fund a loan is $50, so this could be an easy 50% return on that money plus whatever you make off the loan. (If you'd like us to get credit for referring you, please use the links in this post or the right sidebar when you sign up.)