If you use iPhoto '09 and its Events organizational feature in a true events manner--separating your photos by actual event--then you may have stumbled onto a limitation in the current version of iPhoto. Let's say you're interested in creating a photo album for a friend who you've photographed at a number of events. But you don't just want photos that contain your friend in this album; you want all the photos from any event they attended.
While iPhoto offers a plethora of choices when creating a Smart Album, "all events containing person X" isn't one of the options. However, thanks to Mac OS X Hints reader Justin Carter, you can create just such an album with a fairly simple process.
First select Faces from the Library section of iPhoto's sidebar, then double-click on the face of the person you're interested in using for the all-events album. Use drag-select to select all the "known" faces for that person, and then click on Events in the Library section of the iPhoto sidebar.
When you click back into Events, you'll see that any events containing the faces you selected are now highlighted. Click the Plus sign to create a new album, and make sure that the "Use selected items in a new album" option is checked in the dialog that appears. Type in a name for your new album, click Create, and you're done--the new album will contain every event in which the selected person's image appears at least once.
This story, "Create Events-based IPhoto Albums With Specific People" was originally published by Macworld.