The X-10, Insteon, and Radio-RA systems all have listed "lamp dimmers" that plug into a standard receptacle, have provide a receptacle for plugging in a standard lamp cord. There are also plug-in dimmers that are locally controlled. These all provide solutions for plug-in lamps. Although, I don't know if any are designed for low-voltage lighting--I suspect not. For that, I think you're pretty much stuck with the Lutron dimmer/receptacle setup if you need a listed and NEC-compliant solution. If the AHJ is OK with a common-sense approach, I'd think any low-voltage dimmer in conjunction with either a twist-lock or Lutron receptacle would be a safe way to do things.
On the other hand, for undercabinet strip lighting, my approach, if possible, would be to replace the plug-and-cord connected lights with hard-wired fixtures, thereby eliminating a whole host of issues.
[This message has been edited by SolarPowered (edited 02-08-2006).]
