This article appeared in the Guardian on Friday 16 March 2007.

This article appeared in the Guardian on Saturday 5 June 2010.

This article appeared in the Guardian on Friday 6 May 2011.

This article appeared in the Guardian on Sunday 15 May 2011.

A version appeared in the Guardian on Saturday 7 May 2011.

This article appeared in the Guardian on Saturday 29 May 2010.

This article appeared in the Guardian on Saturday 21 May 2011.

It also appeared in the Guardian in an edited form here.

This story, which appeared in The Guardian last week, is really interesting for a number of reasons.

This article appeared in the Guardian on Saturday 6 May 2000.