When I do it, it's a chicken sandwich or a cup of coffee. But when a reader of mine did it a couple of weeks ago, it was a red leather photo album, crammed with irreplaceable pictures of his trip to France last summer.

He left the album on top of his car as he got in and drove away. The album didn't go splat like my sandwich or crash like my coffee cup. But it certainly did disappear.

My reader retraced his steps between Crystal City (where he had left the album atop the car) and McLean (where he lives). Then he tried a classified ad in The Washington Post for 10 days. No soap.

Just as he was about to give up, my reader received a call from a man who identified himself as a truck driver living in Chicago. The man said he had picked up the album on Jefferson Davis Highway in Crystal City on his way out of town. He said he would send the album to my reader in McLean as soon as my reader wired him a $100 reward via Western Union, plus the cost of shipping via Federal Express.

"With some misgivings, I sent him the hundred by Western Union, and waited, and waited, and waited," my reader says. At last, he checked with Federal Express. They'd never heard of the guy.

A classic case of a scammist who reads the classifieds, wouldn't you say? But what would you say if I told you that exactly the same thing happened five days later to someone else?

Another Levey reader, who lives in Alexandria, had lost her dog a few days earlier. She too advertised in The Post's classifieds. She too had no success.

But then her phone rang. Same guy, same spiel. At least this reader declined to send the $100. She reasoned that a sincerely concerned trucker would be very unlikely to cart a dog all the way to Illinois before calling an owner in Virginia. Score one for this reader's common sense.

The D.C. and Arlington police departments say they have received no complaints of any such scam. However, Joyce Richardson, manager of Post classified, told me that her advertisers have been stung by such antics more than once. She said her operators will warn all who advertise in our "Lost" section over the next few weeks that a supposed trucker, supposedly from Chicago, may call to try to fleece them.

Meanwhile, if you ever lose something precious and take out an ad, in the Post or any other paper, you can protect yourself by withholding one key piece of information about whatever got lost.

If a "trucker" calls, and he can't describe the photo on the first page of the album or the mole on the dog's left ear, you can hang up with peace of mind -- and the same $100 you had 60 seconds earlier.

Take-a-bow time for a D.C. cabbie named E.L. Mimms. He did an unusually good deed for a legal secretary named Priscilla Russell.

About two weeks ago, Priscilla hailed the Mimms taxi in front of 1201 Pennsylvania Ave. NW, where she works. She says she almost never talks to cabbies, but on this occasion, she happened to. Among other things, she mentioned that her law firm -- Sonnenschein, Nath and Rosenthal -- is based in Chicago.

As soon as she got out of the cab, Priscilla realized that she had left behind her new $25 Totes umbrella. She said oh nuts. Then she puckered up and silently kissed the umbrella goodbye.

A week later, a fellow SN&R employee happened to hail E.L. Mimms's cab in front of 1201 Pennsylvania. "You work for a law firm out of Chicago?" the cabbie wanted to know.

He soon explained -- and he soon reached down and produced the umbrella, which he had kept under the front seat for a week. Within an hour, Priscilla and her umbrella had been reunited.

To E.L. Mimms, a large rosebud. Not too many cabbies would carry around an umbrella for a week, hoping to find its owner again. And not too many cabbies would remember the Chicago connection after a week's worth of passengers. Nice job!

Your District government at work:

A few weeks ago, a reader from Northwest Washington received a summons in the mail from Superior Court. It demanded that his father appear for jury duty.

Not much hope of that, my reader wrote back. His father had died in 1987.

Two weeks went by. Then came a letter from the court. It said the father's request for a deferment had been considered and denied. He had been rescheduled for jury service in late September.

My reader doesn't know what happened when his father's name was called on the appointed day. Nor does he want to know. All he wants to know is why the D.C. government doesn't cross-check its jury calls against its own death certificates. It would save postage, not to mention credibility.