Hey, good luck with your new tank!
I just broke down my same exact tank a few days ago, doing a 3 gal iwagumi of HC isn't easy. At least it required more attention than I was willing to give. Keep us posted, and here is my journal on it: bitFUUL's 3g High Tech Toilet Tank - (UPDATE - Iwagumi HC with PICS!)
Also, got more info on how you automated the webcam/shots?
I'm not too worried about maintenance. It's at work with me, so I sit right next to it for almost 9 hours a day. I take about a 1 hour lunch break every day, so I have built-in time to mess with it. We'll see how it goes though.
As for the webcam, I'm using a free piece of software called ImageCaster on the Mac. It has a lot of control over size, overlay, format, multiple schedules, etc, and even handles doing a secure copy to my remote web server. One schedule keeps a single image updated every 30 seconds (the one in teh first post), and a different schedule takes a picture every 30 minutes and increments the file names so as to not overwrite previous shots. One month of growth over a time lapse should be about 15 seconds long at 30 fps. It's the only piece of software I'm using, and everything is built-in. The webcam is a Logitech QuickCam Pro.