A patron called the desk asking for the phone number of a laundromat/cleaners in town. She knew it was just down the street from the library, and I pass it every day, but neither one of us could remember the name.
It was lunch time at the library, so there are no coworkers around to ask. I checked the yellow pages under laundromat, cleaners and dry cleaners, but the only businesses listed were not at the address we're looking for. I tried a few internet searches for "laundromat chelmsford" and the like, but had no immediate luck.
If there was another person to cover the desk, I would have just walked up the street and called her back with the information. But it was this thought - seeing the sign from the street - that gave me the brilliant idea of trying Google Street View.
I typed the Library's address into Google Maps, switched over to Street View, and then walked the little yellow man up the block to the laundromat. From this view, I could make out the name of the business (actually, I got lucky and their van was parked in the lot), and from there I could look them up in the white pages.
The patron was not only happy to get the phone number, but amazed at hearing about Street View for the first time. She was so interested that we stayed on the phone for another five minutes while I explained what it was, how it worked, and how she could get to it on her own.
Interesting postscript to this story:
The Chelmsford Library is located on an "island" between two one-way streets. However, this is poorly marked, and I sometimes see non-local cars going the wrong direction. Apparently, whoever was driving the Google photo car is also not from around here. By rotating the Street View down to see the car itself, you can tell by the side mirrors that it's driving the wrong direction - but best of all, you can follow the car's hasty U-turn in the library staff parking lot. Happily this did not cause an accident, but I'm surprised Google publishes photographic evidence of its drivers breaking traffic laws.