Just 4.85% on a 30-year mortgage? Are you kidding me?

That's the rate that Freddie Mac put out this week, as the average on fixed 30-year mortgages hit a record low.

The options are certainly tempting. If you're living in a home that you plan to stay in for a few more years, refinancing is an attractive alternative. If you're in the market for a new home, you have the one-two punch of cheap financing and lower home prices in your favor.

However, you're not entirely out of luck if you have no intention of milking dirt cheap mortgages as an existing homeowner or an eventual homebuyer. You can still cash in as an investor. You just need to know where to look.

Let's start with Bankrate (NASDAQ:RATE). The leading consolidator of interest rate information has been one of the market's hottest stocks this month, soaring more than 60% since bottoming out at $15.77 just two weeks ago. Bankrate feasts when mortgage-seekers hit the site, with loan providers paying well for online leads.

Commercial lenders like Countrywide parent Bank of America (NYSE:BAC) are obvious beneficiaries, but banking stocks may still be a bit too much "mystery meat" for investors.

I prefer to play the trend through nimble online players, rather than taking a risk on real-world companies that may be carrying a ton of toxic assets. See, the dot-com leads don't end at Bankrate. LendingTree parent Tree (NASDAQ:TREE) and Realtor.com parent Move (NASDAQ:MOVE) are probably experiencing huge spikes in traffic this week.

Commercial real estate typically marches to a slightly different beat, but online marketplaces such as LoopNet (NASDAQ:LOOP) and CoStar Group (NASDAQ:CSGP) should also eventually benefit from lower lending rates in general.

In short, you don't need to sit on the fence if you don't have a white picket fence. Mr. Market seems to be throwing an open house.

LoopNet is a Motley Fool Hidden Gems recommendation. LoopNet and Bankrate are Motley Fool Rule Breakers selections. Try either of these Foolish newsletters today, free for 30 days, and see how our house is beating the market.

Longtime Fool contributor Rick Munarriz has been known to chase yields on the Bankrate.com site. He does not own shares in any of the companies in this story. He is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.