Setup an external editor
iPhoto is ok for quick adjustments, however I usually want to do more with my photos than iPhoto can handle. So I set Photoshop as an external editor so that I can edit in Photoshop and return the results right back to iPhoto. Bonus Tip: you can set up the external editor as Photoshop or Photoshop Elements and then switch the setting back to Main Window. Now when you want to edit in Photoshop vs. iPhoto you can right click the photo and chose "Edit in Photoshop External Editor". Otherwise it will edit in the Main window using iPhoto's tools.
Although iPhoto does organization now by Faces and Places, I still like to organize my photos manually in Albums. These Albums sync right over to my iPhone, iPod and Apple TV so that I can quickly show off just the ones I want for a particular event.
Use photos right on the calendar dates
For the past few years now I've used iPhoto to create my family calendars. You would expect to be able to use your own photos on the big page above each month, but you can also drag them right onto the dates themselves. So instead of a name for someone's birthday I have their photo there instead.
Store your photos outside of iPhoto
One of the things that confuses many new users to iPhoto is where the photos are stored. iPhoto by default will "copy" and manage all of the photos that you put into it. These photos are copied to a special folder structure in your pictures folder and if you leave it alone you'll be fine! However, if you want to keep the photos in place and just have iPhoto reference them you can set it to do so in the preferences.
Share on Facebook, Flickr and MobileMe
It's a no brainer that Apple would allow you to share your photos on MobileMe. However, the latest iPhoto also allows you to easily share (and more importantly sync) your photos with the popular social networking sites Facebook and Flickr. What's really cool about this feature is that it's a two way sync. Once you publish your photos to say Facebook and you then decide to add some new photos right on Facebook itself iPhoto will download the new photos directly from Facebook and put them in the same album. Any arranging, title changing, etc. you do in either place will update the other.
Geotag your other photos too
If you have a camera with a GPS or an iPhone, iPhoto now supports that geotag (Location) information. This way you can click a button and be taken to where that photo was taken right on a map. However, what about the thousands of photos you took that don't have this info. Here's a great trick (especially if you have an iPhone), take a photo with the camera that can geotag (here's the GPS unit that I use). If it's your iPhone just take the one shot and then continue taking shots with your regular camera. Now when you get back to iPhoto import all of your shots including the one you took with the GPS enabled camera/iPhone. Right click (Control-Click) on the one photo with the Location information in it and choose Copy from the Contextual Menu. Now select all the other photos taken in the same location and right click on them. Then simply choose Paste Location from the contextual menu. Bam now all of those photos have the same location info in them even though they weren't taken with a GPS enabled camera.
Each time you import photos into iPhoto it creates an event. Sometimes I have photos from the same event on multiple cards. So when I import them I get multiple events in iPhoto which really are the same event. Luckily you can just hold down the Command Key and select each of the events that should be the same and then right click on one of them to choose Merge Events. Now they will all be put into one event.
Delete a photo from an album AND from the iPhoto Library at the same time
It happens I sometimes have duplicates or photos that I just want to get rid of. I see them in an album and that's the easiest place for me to determine if I want it gone or not. If I just delete it from the album it will still be in iPhoto. You can remove it from the Album and iPhoto at the same time by doing a Command-Option-Delete on your keyboard. It will be removed from all albums and the iPhoto Library. Don't forget! You still need to empty iPhoto's trash for it be completely gone!
Automatically Map your photos on Flickr
Flickr has great support for Location (geotag) information in your photos even if you've manually put the info in. However, when you export to Flickr this information doesn't go over by default. You have to turn it on in the prefs. P.S. You may also have to turn on Geotag/Map support in your Flickr account settings as it could be a privacy issue for some. P.S.S. I'm still stunned that the MobileMe galleries still don't Map your photos like iPhoto does and like the iPhoto books do.
You don't have to use iPhoto to manage all of your photos
Guess what? Atter all of this iPhoto is not my preferred app for managing photos. As a professional photographer I use Adobe Photoshop Lightroom. However, iPhoto is GREAT for all of the things I just gave you tips on AND syncing to Apple devices like the iPhone, iPod and Apple TV. I DO use it to make my calendars and such. So this means that I need to have my photos in iPhoto to use all of this magic. So this means that I only put my BEST photos in iPhoto. After I've done all my work in Lightroom and Photoshop I only export the "keepers", the best ones, the ones that I want to share to iPhoto. This also means that iPhoto stays lean and mean. Even if you do use iPhoto to manage all of your photos. Ask yourself, "do I really need all of the photos that I currently have in it?" Chances are you don't. Time to do some cleaning. 🙂
Here's a video I did a while back on how to do this easily from Lightroom: