Then it can be made easily like...
Input-> Tap selection switch-> Step down transformer (with several taps at primary side)-> Rectifier and filter-> Linear regulator-> Output.
But "Joe the mug" never reads the instructions before plugging it in, and wonders for a few seconds why things get very bright, and run really fast..... then go *BANG*
The link was working yesterday, but not today for some reason.
Please note, these are a non isolated dc/dc buck regulator and cannot be used straight off the ac mains supply.
But for less than a dollar are still of very great interest.
*edit*
Here is the same beast on e-bay:
**broken link removed**