[B]ineman loves his EZ430 tool, but he felt that the prototype board being attached close to the debug board was limiting him during debugging. He came up with a cable connecting the proto board with the MSP430F2013 to the debugger. Although you may think that there is nothing great about it, it allows you to use the proto board as a standalone unit. This also allows you to program other compatible chips. Another advantage is that you can now have any kind of connector on your proto board and not depend on the tiny 4-pin Spy-By-Wire connector.

However, he warns about having a long length debug cable:

The 4 wire JTag/SpyByWire interface does not have any error correction in it and is not designed for distances of more than 1 foot, so keep your cable as short as possible. There are several tricks to make it work over longer distances, but to be sure just make it long enough to allow for breakout and then use USB extension cord for distance. I have managed to push it to about 3 feet but in retrospect it was probably not worth it. Anyway, to make it longer you can try.

[Update 11/16/2010]:

[S]impleAvr let us know that he also went a similar path by using jumpers, so that he could switch between boards. Thanks!