I didnt realise this, I should have (kick myself moment for sure!). Like you say it is obvious when you know but when you dont think about then...well...thanks for telling me because this will make my life a little easier. Thanks for the blog :)

Have you noticed if Aperture runs faster when images are referenced instead of stored on the HD? Or any other strategies to keep running Aperture as fast as possible? I'm having problems on my new iMac...

Funny that you bring up performance tips, JL. We're working on a piece that covers some of our favorites. Referenced files with previews can help your iMac situation for sure. What model do you have?

Machine Name: iMac
Machine Model: iMac5,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.16 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache (per processor): 4 MB
Memory: 2 GB
Bus Speed: 667 MHz
Boot ROM Version: IM51.0090.B03
SMC Version: 1.9f4

(Purchased 12/06 after due diligence @ Photo Expo and chatting with Aperture team there.)

So the big question is, can you open more than one library at once that way? :)

I assume not, but that would be pretty sweet, even if it's a complete second instance of Aperture (must... buy... RAM...)

@Jeremey:
No you can't, because each library still accesses resources in the application package itself (located in your Applications folder).
This tip had been shared a while back in this blog, though it was just a passing comment at the time. I'm glad Derrick made a specific post for it..
thanks!

Deathly simple, indeed. Count me as one of the clueness who didn't know it.

I am also grateful to now know. Will save a lot of time.

I love this feature. While I work on the Apple Pro Training Series book (by Ben Long / Orlando Luna, and its great too) I have to switch between my main library and the Training library. A big time saver on my MacBook w/ only 1gb RAm. Aperture run great on it BTW. I only shoot RAW when I want to mess around. My jpegs are ~ 3 - 4MB.

What I found very useful as well is: I made shortcuts of the libraries and dropped them to the right side of the dock so every time I need to launch a specific library I just click on it (I also named them differently and used different icons!). This is indeed a nice trick!

I like Rafael's pile-on about making shortcuts for libraries to make switching even easier. Nice...