Google have added a feature to Google maps that lets you take virtual walks in a city. You can literally follow street paths on a map and have a 360' view of all your surroundings. This feature is called Street View. Click on the images for a quick preview.

From some superficial searches on the subject, the images were taken with video camera mounted on a car, going around the streets. Not all countries have this feature enabled but on August 4th it was introduced for Japan.

This is really amazing stuff! It gives a whole new dimension to travel planning. Images and news about Google Street View found via Japan Probe.

Some sites with interesting street view collections:-
Top 15 Google Street View sightings (Mashable.com)
Google Street View gallery