DR650: off-switch for lights?

[BikingMarco]

In the process of setting up my little Suzuki DR650 for the Africa Tour I installed a 12V socket last weekend. Calculating the max. Watts of things to connect to it I’m sure I’ll be fine. It will only be for some battery chargers and maybe a netbook. However, I was thinking about the advantages of having an off-switch for the lights and quite liked the idea. Not just for saving power but also to be able to switch the bike into stealth-mode. Without having the headlights on which can be seen for km. That would be a handy feature on the last few hundreds metres before deciding on a camping spot or when riding through some dodgy areas.
I am aware that in many countries the law requires to have the lights on whenever you’re riding. But it shouldn’t matter in Africa so much.
So I had a look around at the usual places on the web if there was any info about acquiring an off switch as some overseas models or older models of the DR might probably have. But couldn’t find any.
Do you guys know if such a switch is available somewhere or can you think of a way to make your own?