One of the interesting part with Twitter is its worldwide use. On my Twitter, I usually get European twitts at the end of the afternoon, and South-American twitts during the night.
Comparing my twitting habits with those of my friends, each one of us could have a twitting timezone, that we’ll be surely different even if you live in the same ‘real’ timezone.
Here is a screenshot of what could be the result:
It could be easily done using the API, unfortunatly, Twitter reduce the API use to one request per minute, so it’ll take one hour to build such a timezone with all your 60 friends… but I’m pretty sure someone will have fun to do something like this soon.