The new "patent pending" Float Bowl Drain Valve from Fast Eddy Co. makes winterizing your bike a breeze.  It also makes it waaaay easier to service your carburetor.  If you've ever had to remove the bowl plug to drain your carb, you know how it's virtually impossible to catch all the fuel that comes rushing out once you pull the plug.  You always end up getting gas down your arm and all over your motor's lifter blocks.  Not anymore-  Just twist the valve open and catch it into a small container, all without spilling a drop.  Then you can pull your float bowl, change jets, or complete whatever task you're trying to accomplish.  
 
With ethanol content and other additives in that are in fuel these days, most gasoline has a shelf life and requires the addition of a fuel stabilizer if you still want to be able to use it in a few months.  Additionally, this fuel can build up gummy deposits in many of the small passages that are in your carburetor (such as jets, accelerator pump nozzles, etc).  Draining your carburetor is an effective way to prevent having problems in the spring when it's time to start your bike up again.
 
If you need to pull your gas tank or do some other service work, you can even use the drain valve to empty your whole tank.  Just hook a hose on the valve and drain the entire contents of your fuel tank into a suitable container. 
 
And lastly, this new drain valve makes it easy to dispense fuel into a container when you're in a tight situation- whether it's giving some fuel to your buddy that keeps running out of gas, or just needing a little help getting a fire started at your campsite when you don't have any dry kindling laying around.
 
Winterizing steps:  
1) put small amount of fuel stabilizer in your gas tank
2) shut off your fuel petcock
3) open the float bowl drain valve to drain the fuel that's in the carburetor, ensuring no gunky fuel build-up will form inside the carb over the long winter-