Geotagging photos - first Picasa/Google Earth, now flickr

Picasa 2.5 works closely with Google Earth to make it easy to geotag photos - that is to mark them with the latitude and longitude of where they were taken. That information gets stored in the EXIF data of the photos.

Now a similar feature has been introduced by flickr. This uses mapping from Yahoo Maps (so its worldwide coverage lags behind its USA and Canadian coverage), but the drag and drop interface is quite easy to use.

Lacking an official solution, many existing flickr image had been geotagged by a combination of "geotagged/geo:lat/geo:long" tags - which worked, but was a bit clumsy.  Flickr plan to offer an automated way to remove these old tags, once the development community has had a chance to move to the new model.

Now users has a choice of how to geotag their images - either upload them to flickr, and use the online method there, or perhaps a better solution is to use Picasa / Google Earth to geotag the images before they are uploaded.

Lots of writeups of the feature, including TechCrunch, TechCrunchUK, Yahoo search blog, Thomas Hawk.

Flickr has around 220 million photos (growing at the rate of 1 million per day) - of these, in the first 24 hours the feature was available, geotags were added to 1,234,384 - and by 9 hours later over 1.6 million had been geotagged.

Update: Some interesting comments by the flickr developer Rev Dan Catt at the Ogle Earth report on this, though interestingly nothing yet on Rev Dan Catt's own site GeoBloggers.