I’ve found another informal but telling economic indicator to go along with the iPhone Index and the Roubini Ratio. And this one’s grim stuff indeed.

The Craigslist Misery Measurement emerged in an Associated Press story about people unloading prized possessions online: “At Craigslist, which has become a kind of online flea market for the world, the number of for-sale listings has soared 70 percent since last July. In March, the number of listings more than doubled to almost 15 million from the year-ago period.”

A few years ago, numbers like those could be attributed to the sheer growth of the online population. No more. And Cragislist CEO Jeff Buckmaster acknowledges as much, saying the number listings is “moving above the usual trend line.”

Behind the numbers are some genuinely sad stories:

The for-sale listings on the online hub Craigslist come with plaintive notices, like the one from the teenager in Georgia who said her mother lost her job and pleaded, “Please buy anything you can to help out.”

Or the seller in Milwaukee who wrote in one post of needing to pay bills — and put a diamond engagement ring up for bids to do it…

In Daleville, Ala., Ellona Bateman-Lee has turned to eBay and flea markets to empty her three-bedroom mobile home of DVDs, VCRs, stereos and televisions.

She said she needs the cash to help pay for soaring food and utility bills and mounting health care expenses since her husband, Bob, suffered an electric shock on the job as a dump truck driver in 2006 and is now disabled.

Among her most painful sales: her grandmother’s teakettle. She sold it for $6 on eBay.

“My grandmother raised me, so it hurt,” she said. “We’ve had bouts here and there, but we always got by. This time it’s different.”

And all that detritus from an earlier era of consumer excess is subject to the law of supply and demand. Research analyst Brian Riley from The TowerGroup figures secondhand merchandise is going for 25-35% less than it did a year ago.

Inflation in food and gasoline… deflation in housing and used consumer goods. Sad tidings. And worse is likely to come.