Weird, but true story I heard on NPR.  I checked the Internet, and sure enough there was supporting info.

Once there was a little girl who lived in Staffordshire, England named Laura Buxton. Laura was ten years old on this day, her birthday.

On a whim, Laura Buxton decided to do something sort of like sending a message in a bottle, only with one of her birthday balloons. So, on one side of the helium balloon, she wrote PLEASE RETURN TO LAURA BUXTON, and on the other, her address. Then she set free the balloon, watching it float off into the sky. She thought she would never see the balloon again.

Meanwhile, the balloon had made it across the country and ended its journey when it became stuck in the hedge on the property of another little girl's family in the countryside of Wilt.

The little girl was also 10 years old.

She was also named Laura Buxton.

So the second girl, called "Laura #2", wrote a letter to "Laura #1" - The first Laura got the letter and was shocked. After that, the two girls arranged to meet, and when they did, they were surprised to discover more similarities:

First, they looked alike - They were the same height, had the same hair color, and were dressed in similar outfits, both wearing pink jumpers and jeans. They each had brought, unbeknownst to the other, their guinea pig with them to the meeting. Both guinea pigs were brown and each had an orange patch on their bottom. each girl had a pet rabbit - a gray one, and a 3-year-old black labrador.

http://hubpages.com/hub/PLEASE-RETURN-TO-LAURA-BUXTON