Don't say you weren't warned.

For some time now, I've been pretty critical of FedEx's (NYSE:FDX) plans to "enhance the customer experience, gain market share, reduce expenses, [and] improve profits." (Great ideas in theory, but in practice, management seems to think it can accomplish these tasks through the expedient of raising prices.) I've also received my share of flak from angry shareholders who think that management knows what it's doing -- despite strong evidence to the contrary. Yesterday, I think FedEx proved me right.

FedEx shares dropped 14% two days ago, and fell another 4% yesterday in the wake of a post-market-close earnings warning that FedEx slipped out Monday evening. Briefly, management confirmed that when Q2 earnings come out next week, FedEx will hit near the top of its previous guidance for this quarter's earnings -- $1.58 per share -- but fall far short as the year progresses. Fiscal 2009 guidance got slashed about 18% and now sits in the $3.50-to-$4.75 range; management appears to be seeing a much tougher second half than previously expected.

Why? Said CFO Alan Graf: "Demand for our services weakened sequentially throughout the quarter and global economic trends continue to worsen."

Granted, the same "rapidly declining fuel prices" that helped out in Q2 should continue to boost results through H2. Granted, too, the price hikes that FedEx is pushing through (in the face of falling fuel costs, no less -- or did I mention that already?) will help stem the declines from lower demand. Regardless, management seems sufficiently worried by the economic trends it's seeing that it is once again cutting expenditures, battening down the hatches against an economic storm that's already struck. Fiscal 2009 capex targets dropped again, from $3 billion at last report to $2.5 billion today.

What's a Fool to do?
First and foremost, do some battening-down of your own. Where FedEx leads, UPS (NYSE:UPS) tends to follow. So if you own Big Brown, it's time to reconsider the wisdom of that decision.

Second, consider who uses these companies' services. Or more to the point, who isn't using their services as much as expected. Review FedEx and UPS's customer lists, and consider whether a slowdown at the nation's two biggest publicly traded parcel carriers might not portend bad news for shipping customers like PetMed Express (NASDAQ:PETS), PC Mall (NASDAQ:MALL), Cabela's (NYSE:CAB), and Zumiez (NASDAQ:ZUMZ).

It could be that there's still time to get ahead of the curve on this here recession, and spare yourself some pain.

To prepare for FedEx's earnings next week, read up on what happened last quarter:

Zumiez and Cabela’s are Motley Fool Hidden Gems recommendations. United Parcel Service is a Motley Fool Income Investor selection. FedEx is a Motley Fool Stock Advisor pick. Try any of our Foolish newsletters today, free for 30 days.

Fool contributor Rich Smith does not own shares of any company named above. The Motley Fool has a disclosure policy.