You know, nobody loves a good “buy stocks when they’re beaten down” diatribe more than I do. And to be honest, I agree with the underlying motivation — the time to buy a stock is when nobody else wants it and it’s at a multiyear low.

This argument has been made plenty of late, too, encouraging purchases of social networking stocks like Facebook (NASDAQ:FB) and Zynga (NASDAQ:ZNGA), both of which are near painful lows after their initial public offerings. Fair enough; they’re dirt cheap now compared to where they were.

Yet, I can’t help but wonder if investors have collectively fixated so much on the social networking theme lately that they’ve forgotten something more important, even if it’s discussed less often. What’s that? While grabbing stocks at bargain-basement prices is one thing, whether they’re worth owning at any price is another matter altogether.

With that in mind, might I make a suggestion? Though social networking is all the rage right now and some traders are gleefully scooping up shares at rock-bottom prices, there’s another group of stocks that are also at multiyear lows that make far stronger long-term bullish cases.

It’s the solar panel industry — and though it has doled out more than a little shareholder pain over the past 12 months, I feel much better about buying those new lows than rewarding Mark Zuckerberg for his IPO whiff.

Yikes, But …

Take your pick — it doesn’t matter. First Solar (NASDAQ:FSLR), SunPower Corporation (NASDAQ:SPWR), Suntech Power Holdings (NYSE:STP) and most of the other major solar stocks are at or near new multiyear lows thanks to the end of supporting government subsidies and the plunge in natural gas prices. A glut of panels (thanks to too many new players coming in right at the peak of demand in 2008) didn’t help the industry, either.

As is the case with … well, pretty much everything that has to do with any economy, the pendulum repeatedly swings in both directions. Investors went bullishly overboard with solar power stocks up through 2008, and then overshot with the selling since then. Now that the dust is settling, though — and now that nobody really cares anymore — the pendulum is poised to swing in a bullish direction again. This time around, however, investors have balanced their euphoria with a healthy dose of fear surrounding solar panel makers.

The proof of the modest rebound comes in the form of new contracts, which are gradually getting bigger. As an example, LDK Solar (NYSE:LDK) was just awarded a 600-megawatt construction deal in China, whereas contracts for 10 MW and 20 MW were big deals in 2011. In fact, despite the recent contraction in global demand for solar power panels, China actually ramped up its demand by one full gigawatt last year, and forecasters are saying the country is going to install 3 GW to 4 GW of new solar power capacity in 2012. Global demand for new installations is expected to rise from 27 GW last year to 32 GW in 2012. There’s even budding demand in the Middle East.

Point being, although the industry still has a ton of work to do (and too much capacity to shed) before competing with uber-cheap natural gas, there are enough pockets of strength here to get — and keep — stronger solar players viable again.

Is Solar Really Better Than Social Networking?

Back to the original point: With both groups of stocks at new lows, is an investment in solar power now a smarter move than an investment in social networking? As tough as it might be to swallow the pill, yes, it is.

Though the supply and demand levels still are mismatched, solar is a real industry based on real demand. Moreover, it provides something we’ll always need: power. Natural gas eventually will run out, or face a price hike that makes it unaffordable. Solar’s always going to be there, though.

Granted, solar profitability still is inconsistent at best, even down to the individual company level. But with nearly a dozen major PV panel manufacturers declaring bankruptcy in the last 12 months or so — unable to outlast the impact of the end of subsidies — that attrition is slowly but surely redirecting sales to the remaining players.

Social networking, on the other hand, relies on consumer trends and cultural fads, which always are changing. Worse than that, there are minor signs that Facebook already is peaking in terms of interest and activity. Besides, even though Facebook certainly can draw a crowd, it along with most social networking sites have faced big challenges in trying to monetize that traffic.

There’s no barrier to entry either, which is largely how MySpace was ushered from the head of the class to the back of the line when Facebook started to hit its critical mass. Why couldn’t something do the same to Facebook?

I’m just sayin’, if you’re going hunting for long-term bargains, at least start with an arena that has the better shot at justifying higher values in the future.

As of this writing, James Brumley did not hold a position in any of the aforementioned securities.