10W 1.25-13V(adj) 1A DC-DC converter

[koala]

Linky - Dimension Engineering

I think.. Although this is a voltage regulator, you can actually adjust the voltage to control the LED current.
If you know the vf of your LED, this will supply 1A current at the specific output voltage. Or just adjust the screw to increase the voltage till you reach 1A or the current desired. Could be useful for anyone here. Also check out the other types of DC-DC converters listed on the left of the webpage.

 

[sv_ted]

I am using a couple of these to replace batteries on my bike lights that require a constant voltage input. For LED's you are much better off with a constant current regulator such as a BuckPuck. As the LED turns on the current draw increases quickly with applied voltage. You will have a hard time controlling the current accurately with a voltage output converter.