I used some parts from an old broken laser flashlight kit, also used a old crybaby pedal switch for the main on and off, the driver I ordered off of eBay (they are cheap and small). I plan to convert it to a laser graffiti build later, I also have an arduino installed to the ttl for the graffiti but its not used right now.
Thing is a beast, I can run it off a 9v but it burns through the batt pretty quick so i use a wall supply.
2W (not really good for 2W more like 1-1.5) 445nm M140 Blue Laser Diode
In Copper Module W/Leads
445nm Laser Diode Driver
For 50mw-1000mW LD/ w/h Current adjustor & TTL Input
Wires and connectors
Stolen from an old plotter
Nice wooden box with hinged lid and clasp.