Andy, some "wall warts" (normally the AC-to-AC ones only; essentially a stepdown trafo without the rectifier & filter assembly for converting to DC) have a pair of screw terminals to attach wire to them.
These are commonly used for alarm installations and sometimes come with a little tab on the opposite end so you can put the wall plate screw for a duplex American recptacle through them and that way they remain plugged in permanently (permanent in the sense that you need to first undo the cover plate screw before you can pull the plug).
The AC-to-DC (trafo with rectifier & filters) and most other AC-to-AC warts for consumer equipment have a hard-wired cord going through a strain relief bushing.
[This message has been edited by SvenNYC (edited 12-31-2003).]
