wiring/connecting for beginners

[Pev]

I would like to try and use my TomTom 700 on my bike (without the sound as there is no audio outlet connection from this unit). I think I can fit it on the bars ok using a spare windscreen adaptor but where can I get a suitable connector to connect up the 12v cigarette connector into the power socket?
When others have hard wired their GPS units directly to the battery or ignition switch how have they reduced the voltage down to that required for the GPS, ie the cigarette connector for my TomTom has an output of 5v & 2 amps.
Cheers
Pev