"Don't catch a falling knife," as the old saw commands. (Pardon my mixing a cutlery metaphor.) The idea of buying a former superstar stock at a discount price certainly has its attractions, but you've got to make sure you catch the haft -- not the blade. That's where Motley Fool CAPS comes in.

Today, we once again stand beneath Mr. Market's silverware drawer, measuring which knives have fallen the farthest. Then we'll call on CAPS to ask which of these stocks -- if any -- Foolish investors believe are ready for a rebound. Let's meet today's list of contenders, drawn from the latest "52-Week Lows" list at WSJ.com:

Stock

52-Week High

Recent Price

CAPS Rating
(out of 5 stars)

Integral Systems

$27.00

$7.35

*****

Opnet Technologies  (NASDAQ:OPNT)

$14.39

$7.99

****

Nabi Biopharmaceuticals  (NASDAQ:NABI)

$6.16

$2.40

***

Laclede Group

$55.81

$31.37

***

H&R Block (NYSE:HRB)

$27.97

$13.94

*

Companies are selected from the "New Highs & Lows" lists published on WSJ.com on Thursday and Friday last week. 52-week high and recent price provided by Yahoo! Finance. CAPS ratings from Motley Fool CAPS.

What goes around, comes around
This week's list of 52-week low-scrapers contains a couple of names that should be familiar to regular Fool readers. Top-rated Integral Systems, for example. I profiled this Boeing (NYSE:BA) and Lockheed Martin (NYSE:LMT) subcontractor just a few weeks ago in Drop-Dead Gorgeous Stocks, in honor of the stock's falling to not just a one-year, but a five-year low. (It's up 11% since.)

Little point in rehashing that story again today, so instead we'll turn to another familiar face. Eight months ago, Opnet Technologies was riding high -- a 52-week high to be precise. Back then, I asked whether Fools expected it to fall, and got a negatory response.

Well guess what? It did fall. Hard. But could this provider of "network management software" be ready to rise again? That's what we aim to find out, as we examine ...

The bull case for Opnet Technologies
Opnet got a big endorsement from CAPS All-Star ping898 back in July of '07. Apparently having firsthand familiarity with the company's products, ping898 told us that Opnet makes "[h]ard to use software, but when used right, very effective."

bikodoggy agreed later that year, adding: "Good products, big partners, buyout candidate?" And it could well be. With its enterprise value of less than $75 million, strategic partners Riverbed (NASDAQ:RVBD) or Texas Instruments (NYSE:TXN) could easily buy the company with their cash-on-hand, if they were so inclined.

Of course, that would probably require that management like the price. As CAPS All-Star Trimalerus pointed out last month, Opnet's "[i]nsider ownership is just above 36%." But Trimalerus sees this as a plus, and also likes the firm's "[t]rustworthy accounting."

Best not to place your hopes in a bailout, though (we can't all be Citigroup). If you're considering investing in Opnet, you want to first make sure that the stock stands on its own as a quality company. The good news here is: It does.

Oh, I get that the firm looks expensive, what with its 35 P/E and all. But what you don't see reflected in that P/E is the fact that Opnet generated $8.2 million in free cash flow in 2008, and so sells for an enterprise value-to-free cash flow ratio of less than 10. Considering that analysts expect this firm to grow its profit at 27% per year over the next half decade, that makes the stock look quite cheap indeed.

And even if it takes a while for the bounce to materialize ... did I mention that Opnet pays its shareholders a 4.5% dividend? I'd wager that's a whole lot better than you'll get for depositing your money in a bank for the next five years. And it's yet another good reason to buy Opnet today.

Foolish takeaway
Of course, the aim of this column isn't just to tell you what I think about Opnet Technologies -- or even what other CAPS players are saying. We really want to hear your thoughts. Click on over to Motley Fool CAPS and tell us what you think.

Motley Fool CAPS : It's fun, it's free, and it just might make you famous.