If you like photos, Flickr, and OS X, and don’t know about FlickrExport, then shame on you. It’s a nice little plugin that will let you easily export photos from iPhoto to Flickr. It converts your assigned iPhoto keywords to Flickr tags, enables you to add titles and descriptions, and choose to either add the photos to a new set, an existing set, or none at all – all within the dialog window.
The one rub is that it is made by an independent developer, Fraser Speirs, who has to feed his family – so, he charges about $25. A nominal price for something that has saved me hundreds of hours, and enriched my Flickr experience.