I'm certain many people of the same problem. Not being able to search for a photo in your photo app is extremely stupid. The same is true of viewing your photos on an Apple TV using iTunes -- No ability to search for anything! Just a bunch of "events" presented one after another. If you configure iTunes to display photos on the ATV using iPhoto, you get one top level directory, then a jumbled mess of events, again with no way to search for a photo.
I've used iPhoto for years, and I just switched to Picasa. You simply tell Picasa which folders you want to scan, and everything is automatic after that, i.e., if you add photos, modify photos, or delete photos, it's all automatically updated in Picasa. In iPhoto to get some semblance of a directory hierarchy, you need to create a folder, then drag stuff to it. Even then it's only one level deep. Very messy. Of course the Apple juice drinkers in this forum will tell you that you just don't understand how iPhoto works. What nonsense. Picasa and Lightroom got it right, iPhoto did not, in my opinion.