Google Picasa 3.8 [mw] full review
Picasa is a real alternative to iPhoto. The program imports media either from the common photo folders or by scanning the entire drive.
This is something of a blunt instrument approach, as it will pick up every single graphic or video file on your Mac. Everything is listed in folders, as the system tries to sort out what you have and organise it by year, as people or places. The people function is clever, scanning and recognising groups of faces. These can be tagged and named or removed from the People album.
Adding a location to a photo is easy thanks to integration with Google Maps