It took me two visits - maybe this list can save someone else the hassle of multiple trips:

• Blank company letterhead - and you then write down a list of what you have ordered on it for them. This was required for a limited company (and its omission was why I had to go back)
• Proof of trading with address - I used a company bank statement
• Company debit/credit card
• Driving licence
• PAC code from previous network (if porting an existing number across)

Following last week's launch of Apple's Safari browser for windows, I've noticed the continuation of a pattern that I was hoping would stop with iTunes for Windows. Why on earth do Apple insist on using a non-standard window chrome design, making the buttons much smaller?