Share iPhotos on a Mac with Facebook, Twitter, and Flickr
By clicking Share, you can upload pictures from your Mac to the wildly popular Facebook social network or add images to one of your tweets. If you go with Facebook, pictures can end up on your Facebook timeline or in designated Facebook albums. You can even change your Facebook profile picture from iPhoto.
If your Facebook friends happen to comment on the pictures you’ve shared in Facebook, you can read those comments right in iPhoto. If Facebook friends tag names of the people in your pictures, those tags are synced to your iPhoto library (and yes, you can add those monikers to Faces). If you name the people in the pictures you’ve uploaded through Faces, those folks are notified, too.
Highlight the picture, click the Share button, and choose Facebook from the menu that appears. Select where you want the picture to land on Facebook: your timeline, an existing album, or a new album. You get a chance to type a comment before clicking Publish to post. And you can choose who on Facebook can see those pictures (Everyone, Friends of Friends, Only Friends, or Only Me).
If you go with the popular microblogging Twitter service instead, your photo is attached to a Twitter share sheet. You can add your location and type a tweet to go with the picture — not exceeding the maximum characters.
You can transport your pictures from iPhoto to the Internet cloud in other ways, too. If you click Share, you also have the option to publish photos to the Flickr online photo-sharing site. You need a free account for this purpose, which you can set up by using your Yahoo! credentials, if you have them; Yahoo! owns Flickr. On Flickr, you can place the photos in Sets.