What is the easiest way to tag photos for iPhoto? It would be nice if there was some sort of tagging system similar to the one Facebook uses to tag people, and then be able to search people or locations.
iPhoto does exactly as you've described.
Here is what I do: Each photo gets tagged by (1) The kind of photo either Underwater, landscape, cityscape, portrait, groupshop, still life or whatever. I have a fixed list of these and (2) The location but I assign the same location to an entire "roll" and will divide the roll it it was shot at multiple locations. (3) By subject
This goes fast because in iPhoto you can select multiple images and assign them all the same keywords. So for example I can select all the images taken in my underwater housing and assign the "underwater" keyword to them. and then select all the ones of rock fish and give then a tag. I select and entire roll and give it two stars and then"promote" the rating as a look at them.
I have edited the keywork list to include what I need to do the above and think carfully before adding more keywords, it has to be in a "system" in order to work.
I use the comments field for stuff that can't be done with my keyword system.
I also wrote down my star rating system. Say three stars is a good but un-artfull snapshot, four is a good photo and 5 is what I'd concider publication quality
Any system will work but you have to think it through and stick to it. It helps to write down your "rules" so that they will remain consistent over the years.
I'm stil using iPhoto because my two G4 Macs don't like to run Aperture well. I'll upgrade when Apple builds something comparable in price and form factor to the old PowerMac (remember the $1,400 tower with upgradeable parts Apple sold in 1999?)