Also I would like to add that DESPITE the fact that most camera manufacturers tag their images "ColorSpace: RGB" in the Exif data, most consumer camera preview LCDs ARE UNCALIBRATED, not to sRGB nor to anything else, and they are CERTAINLY not showing you your picture with the so-called "sRGB ColorSpace" taken into account.
So if you think you are looking at your pictures in sRGB on your camera's LCD, you are probably mistaken.
My Canon Powershot A75, for example, labels all its images with a gamma of 2.2 (i.e. sRGB), and yet the LCD on the camera happens to have an almost identical gamma to my iMac LCD.
So basically, this entire discussion is moot, because the so-called "standard" sRGB is not a standard at all in the camera world, and cameras will happily label their images sRGB while providing you with LCD images that are as far away from that as possible.
The result is that even if my entire system is completely, perfectly calibrated to sRGB, my images will all look way darker.
My solution was to just apply the damned iMac LCD profile to all my images, since visually it provides to the closest results of all my profiles (makes sense doesn't it -- it's an LCD), and all the "experts" who recommend doing things by the book? I laugh in their faces.
Let me say what most of you know but are struggling to find a way around.
It is completely pointless to try to standardise any workflow to the sRGB standard used in cameras, because this standard is a ruse. It doesn't exist. It's a fiction. It's a labelling standard, NOT an engineering standard.
All the camera manufacturers just build it however they like and then label it sRGB.
This is a fact.
And if you want to get the colours you're looking for, you will be wisest to completely ignore the profile on any image tagged 'sRGB'.
If you read this analogy you will have perfect understanding of the value of the "sRGB standard" and the futility of expecting iPhoto to automatically profile digital camera output.
Imagine photos are eggs, and iPhoto is a grocer. This thread reads kind of like the follow.
User: "You're applying to wrong size label to all these eggs. You labelled them all Medium." iPhoto: "What should I have labelled them?" User: "Large." iPhoto: "Why?" User: "Because they are oval." iPhoto: "How does that make any sense?" User: "The sRGB egg standard dictates that all large-sized eggs be identified as such by being presented in an oval manner." iPhoto: "Er ... aren't all eggs oval?" User: "Yes, but this is obviously because chickens have decided to all hew to the standard." iPhoto: "Er, I don't think any actual physical changes are made in the eggs, no." User: "Well then ... which label will describe this collection of eggs most accurately? Yours or mine?" iPhoto: "I have no idea."