Tagging makes finding things easy. iPhoto Keywords are great for tagging your images. The drag/drop that's usually required can be time consuming. Here is a quicker way to do it.
1. Open iPhoto
2. Select your photos that you want to add a group of keywords to.
3. Photos -> Get Info (or COMMAND I).
4. Click on the 'Keywords' tab, and then add check-marks next to the keywords you want to tag the selected photos with. When you are done, close the dialog box.
