Say you're writing a story and you've got three characters. One of them is 82 years old, another is 67 years old and the third is 16 years old. You need to choose names for these characters that match their personalities but you also need to make sure they're plausible names for the decade the character was born in. How can you check? Simple! Use this site:
NB: You need to have Java enabled in your browser for it to load.
Once the page has loaded just enter your chosen name and press return and the graph will shift to show you how popular that name was in the decade your character was born.
e.g. "Sandra" was a very popular name in 1940 (one of the top 6 names) but was very rare in the 1920s (rank 562) and has obviously fallen out of failure in recent years too (rank 364 in 2006). So - Sandra's a very plausible name for your 67 year old!