"NASA is deeply committed to spreading the unique knowledge that flows from its aeronautics and space research...." and the evidence its webcams are  here to see.
Kennedy  Space Centre

List of local authority webcams from around the world but also includes list of local  authority websites
Local  authority webcams

Searchable directory for Online cameras.
Online  Camera

Oxford circus updated every five minutes
Oxford Circus

BBC  News Online's special webcam offers a round-the-clock, constantly-updated view of Britain's symbol of the new century - the Millennium Dome in London's Docklands. It can be viewed night and day, wherever you are in the world
The Dome

The  definitive list of things webcam!
The webcam resource

Comprehensive list of webcams around the UK - include the Big Ben webcam which was nominated in the Worlds top 25 most interesting webcams by a  prestigious panel of industry experts in the USA.

A  view of wembly stadium from Brent town hall - unfortunately you can't get a free view of the football matches or concerts from this camera 
Wembly stadium