Many of the banks from home are affiliated with banks here in the United Kingdom.  
What this means is that you can get your local branch back home to help you open
a bank account in the UK before you arrive here.  A reference from your home bank
does wonders in proving your credit worthiness - so why not have your bank earn it's keep
for a change?

Known Affiliates:

                                 

New Zealand	Australia	South Africa	United Kingdom
none	National Australia Bank	none	Clydesdale
ASB Bank	none	none	HSBC
National Bank	none	none	Lloyd's TSB