On Tue, 22 Jul 2008 12:04:13 +0100, Roland Perry
wrote:

In message , at 11:52:34 on Tue, 22
Jul 2008, Walter Briscoe remarked:
What is the shortest journey between a pair of distinct stations on the
Underground?

The quickest (between Oyster validators) is probably Northfields to
South Ealing as they are both surface stations. The platform ends are
about 200yds apart.

Though the exits from the platforms are at opposite ends of the
platforms.