Updated May 17, 2013, see below.
I built this radio in July 1999 to send to Owen Pool, who has a great crystal radio website. He had some simple radios on his site and somehow we started corresponding. I put this radio together in about an hour. It is built on an old shingle, with a popsicle stick regeneration control and a toilet paper tube for a coil form.
The circuit differs from the simple regen I built for 40m in that it works on the AM broadcast band. It worked better with the tickler in the source circuit. Don't know why. The tickler is wound on a short piece of toilet paper tube glued to a popsicle stick. A screw near one end of the stick lets you swing it around to control proximity of the tickler to the main coil. The antenna is just a 6 foot piece of wire. Like the 40m set, you unplug the phones to turn it off. This radio also uses the DC resistance of the phones for the bias resistor, so you need to use real 2K phones. An alternative is to make a parallel combination of a 2K resistor and a high impedance crystal earphone. That works OK.
Well, I sent that radio to Owen, so I never really got a chance to mess with it to see what it could do. I built one for myself, but with a rotating tickler arrangement this time. Same basic thing, but the main coil was wound with 65 turns on a used salt box tube.