– [BBC News summary](http://news.bbc.co.uk/1/hi/uk/4659331.stm) of the bombing.
– [Guardian Eyewitness Reports](http://blogs.guardian.co.uk/news/) are useful.
– [Londonist coverage](http://www.londonist.com/archives/2005/07/tube_network_do.php) – all of their staff is out reporting, so it’s been particular quick and up to date.
– A [Technorati search for “london explosions”](http://www.technorati.com/search/london%20explosions) will give you all relevant blog posts.
– WikiNews has [particularly good coverage](http://en.wikinews.org/wiki/Explosions%2C_%27serious_incidents%27_occuring_across_London), as [does Wikipedia proper](http://en.wikipedia.org/wiki/2005_London_transport_explosions)
– [London Bomb Blast pool on Flickr](http://www-us.flickr.com/groups/74918957@N00/pool/) for related photos.
My thoughts and prayers are with those in London today.