I usually check this stuff with the <a href="http://www.socialsecurity.gov/OACT/babynames/" target="_blank">Social Security baby names site</a>. I looked at the popularity of "Vivian" across the last few years as well as how it ranked in the 90s and 80s. For the past few years Vivian has hovered around #220-230. To me, that indicates a name that is not exceedingly rare, but also not terribly common. You would probably occasionally meet another child named Vivian, but it would be unlikely that there would be two or more Vivians in your kid's kindergarten class. Looking at the 2005 list, I'd say the names in the top 100-150 are the ones that I meet kids with those names all the time.<br><br>
It looks like Vivian's popularity has been on the rise over the past couple of decades - it around 500 in 1985, the 300s in 1995. My DS1's name has very similar numbers. I don't often meet another kid with his name, but it's not considered totally unusual by people and sometimes I meet people who know another child with that name.<br><br>
I don't know any children named Vivian, and I think it's a very pretty name!