Here's what a street in Paris looks like (click any image to see larger version):
You can also move around your location, street by street, block by block, and zoom in and around in all sorts of interesting ways. If you've never had the chance to explore a particular city or other location and/or can't travel there, this allows you to take a virtual walking tour of most places (there were a few places I tried to pull up that only offered a still shot, so it seems Google hasn't mapped every square inch of the Earth (yet).
I can't tell exactly how old these street views are, but I'd say probably at least six months but no more than two years old (if there is a note of exactly when the images were taken I didn't bother to look for it.) While faces and license plates are mainly blurred out, businesses, signs and other details are not. Here's a street where I used to go shopping in San Francisco's Chinatown:
I think this service is especially helpful for writers if you want to include a setting in your story that is a real place you've actually visited but haven't been back to visit in a long time. There was this spot out on the west coast where I used to sit and watch the sunset that I wanted to use in a story. Unfortunately I lived there many years ago, and as much as I'd love to go back there, I don't have the time or justification for the expense.
Relying on my memory, I wrote the location into the story with a lone bench, some rocks and the water. When I pulled up that spot on the street view, however, I saw that someone had put up a big ugly fence near my bench:
It takes some practice to learn how to use the different symbols and zooms to move around your street view, but I think it's worth taking the time to play with and learn. Plus if you can't afford to take a research trip, it may be the next best thing to being there.