There are such devices as `television standards' converters used for that very purpose. And since the television industry is going all digital, it probably won't be long before you can get a used one on Ebay or through some other broadcast equipment supplier.
One of the other ways, is by using your computer and making the conversion through either a software application or possibly even a particular make and type of video card. For instance, my ATI video card can play either NTSC or PAL, and I've seen quite a few free proggies on the net for doing standards conversions. But, you gotta spend some time diggin' for em because they're up against the commercial software makers.
You may be better off just trying to convert your video into a different format, such as .wav. Divx, Quicktime, etc. using your computer. Then take if from there.
Too many options and plenty of ways to experiment to get the results you want.