I've been geotagging many of my photos on Flickr, but it's always bugged me that the geolocation metadata was not available in my Aperture library - geotagging only happened after posting photographs to Flickr, and that metadata was essentially lost from my library.
That just changed. Now I'm using the awesome new Aperture geotagging plugin Maperture, adding latitude and longitude data directly within Aperture before uploading to Flickr etc... That means I get to keep my metadata.
Here's what the Maperture metadata entering screen looks like:
[caption id="attachment_2132" align="aligncenter" width="640" caption="geotagging in Aperture with Maperture"]
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and once posted to Flickr, the geotagging data is still available:
[caption id="attachment_2133" align="aligncenter" width="640" caption="displaying the geotagged data from Flickr after posting"]
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And, thankfully, the coordinates seem to match up pretty closely. I'd tried using Google Earth via the Flickr Export plugin for Aperture to add the geotag data before, and there was a mismatch when viewed on Flickr. Maperture seems to work great so far!