Tom_Cash - 11:09 am on Jun 1, 2011 (gmt 0)
My personal preference is to have the www. - but I'm of the understanding it doesn't make much of a difference provided your website makes a proper use of 301 status codes.
I also think www. is the preference of most websites out there.
But as long as you redirect your user correctly and quickly, I guess it doesn't matter.