After Apple published new iPhoto for iOS in March it appears that they moved from Google to OpenStreetMap data for the map tiles tho at the time there was no attribution given to OSM. With the latest release of iPhoto this was addressed and as OpenStreetMap tweeted and also confirmed it on their blog Apple now lists OpenStreetMap contributors in the long list of acknowledgements for the app.
The OSM Foundation told TalkingPointsMemo how it managed to get attribution from Apple:
The OSM Foundation has made informal contact with staff at Apple and, in addition, one of our volunteer mappers who is an iOS developer spoke to people at Apple. We believe it was the latter that precipitated adding the attribution – it’s great to have such an active and engaged community!