My iPhoto Backup Dilemma

I love iPhoto.  The fact that it’s included with every Mac makes me all the more happy.  However, while I much enjoy a streamlined and feature-rich application to manage the wealth of photos that I’ve taken in the past year (nearly 10 thousand), I’ve reached an impasse of sorts with the software.

You see, iPhoto stores all of your photos, both originals and modified, within an iPhoto Library package that’s stored within the Photos folder of your home directory.  When I first came to this discovery in my ‘honeymoon’ phase of enjoying my iMac, I thought this was fantastic!  All of my photos were clearly being kept track of by iPhoto in one neat container that I could navigate to easily should iPhoto ever go belly-up for whatever reason.  However, while Time Machine does a great job of keeping all of this data securely backed up with its periodic jobs, I’m more concerned with space than the security of data at this point.

My iMac, regrettably, has only a 320GB drive while I’m taxing a 1.5TB external for larger files such as video or software packages.  My original plan was to backup the iPhoto library package in its entirety at the end of each year to the external drive, wipe the existing photo data in iPhoto and start clean amassing what would at the end of the year be another yearly iPhoto backup.

While this seemed like it would work without a hitch, now that 2009 is at it’s end I find myself scratching my head.  If, in the future I have a new Mac with a much larger internal drive and I want to see all of the photos I’ve gathered over the years, will iPhoto choke if I try to import multiple libraries?  Will they cause a conflict or overwrite each other?

As much as I’ve learned about working with the Macintosh platform I’m still fairly new to the Apple tea party.  Have any of you experienced similar problems in sorting out your data storage?  What methods did you use to refrain from eating up all of your local storage?