O2 Mobile Broadband (UK)

A SIM with no instructions and it's a little tricky to figure out how to connect to O2 Pay & Go mobile broadband.  These settings worked for me:

APN	m-bb.o2.co.uk
Username	o2bb
Password	password
Number	*99#
Authentication	PAP

Then go to https://mobilebroadbandaccess.o2.co.uk to check your balance, top-up, etc.  I assumed I had to create a "My O2" mobile account, but that doesn't appear to work with mobile broadband.