Where tweet shows the last 100 geocoded locations that someone has tweeted key words or phrases in the last 24hours, and then plots them on a map.
This should show geographical trends in certain events. If you want to see if it's just started snowing in Detroit, just open up whereTweet.com/Snow and see if the map has a lot of tweets over Detroit.
The searches are cached, and update only every minute or so, this is just to stop us from tripping the Twitter Search API limits, we use Twitter Search API, Yahoo Place Finder for geolocation to Long/Lat, Google Maps for the map display, (and v2 MarkerClusterer for the location clustering - although it's off at the moment).
Since all tweets with "New York" as their geolocal will post on top of each other, we use an algorythm that distibutes marks on a curved path (in case it looks weird if you zoom in and they're all lined up.)
This site is another Only Slightly Useful web site. Conceived, created and coded by Jon Sykes.
If you have any questions, comments or suggestions of other things we should track, drop us a message on twitter @slightlyuseful