As a professional webdesigner you collect and deals with not just 10 photos a day.. It can go beyond that, it can reach around 100-500 images per day if not more, my point of view is that your'e just stupid or like to use time differently then the rest of us if you don't use a image browser program in any form..
On Mac there is Apple's own iPhoto with it's recent version 5 it's probably the best tool outthere! Sure it's got compeititors like ACDSee on the PC and several others but noone has more functions, more capabilities then iPhoto 5.
iPhoto 5 has it's orgin in the iLife 05 package which contains several other programs just like iPhoto but they not into photo, but all bundled and seemless working together if you want them to corporate with eachother.
The common sense about iLife 05 is that they are great for consumers not professional but think again, no other image browser software can you make your portfolio book in and no other can you order prints directly from the program to get delivered to your door without moving your sorry ass from your beloving mac and you can just sit there and drink a nice beverage and think.. Poor guys working on PC's..
My personal use for iPhoto 5? I use it daily, got my own photo library in it and it's really great.. But I hope iPhoto 6 will leads us in the next version of Mac OS X 10.5 Leopard.