As a space nut, I'll chip in
Terra and Aqua, two earth-ob satellites both have instruments called MODIS. Roughly speaking, they each take photographs of the entire world, once a day, at about 250m/pixel
http://rapidfire.sci.gsfc.nasa.gov/
There - you can see the raw data in near real time every day. It tends to look a little odd, especially near the edges of the images, as it's not map-projected. There's also a very large selection of automatically map projected regions, and the 'gallery' of specially picked images, like this awesome one of us under the snow.
You can actually have that image at 250m/pixel
http://rapidfire.sci.gsfc.nasa.gov/gallery/?2010007-0107/GreatBritain.A2010007.1150.250m.jpg
The cities stand out very well, and when it's not snowy - so do the major airports.
As for the UK, without snow, in the clear...well...nearly
http://rapidfire.sci.gsfc.nasa.gov/...efl2_143.A2007085130000-2007085130500.2km.jpg
What's really good with these cameras is watching evolution of things like wild-fires, dust storms, algae blooms, and of course the deposition and melting of snow.
For more 'oh, COOL' - try:
http://www.nasa.gov/externalflash/eyes/
With that - you'll see Aqua, Aura (a close relative of Aqua and Terra) and others flying on the same orbit - called the 'A-Train'. Believe it or not, they have several satellites all chasing one another, so that they collect data of the same places at the same time so it can be combined.
http://en.wikipedia.org/wiki/File:A-train_2009.jpg
Oh - and I'm currently sat in Heathrow Terminal 1 (coach down from leicester was fine, and 95% of flights look to be going ahead) - waiting for a flight to LAX for an interview to work with the very team that made Eyes on the Earth 3D (and CASSIE -
http://saturn.jpl.nasa.gov/multimedia/CASSIE/ ) in Pasadena

(Hint - you'll need to fire up Safari in 32 bit mode to download and use the unity plugin. )