I actually run an original C2D iMac next to an original G5 iMac (which is a file/print server). I have the G5 setup as a second monitor using Screen Recycler.

It's not fast but it's perfect for reading email, IM, Photoshop Pallets, etc.

My only complaint is the Screen Recycler is forced to sit in my Dock. It'd be so very much nicer to have it as a menubar item.

Cheers

If you pay the powerbill, It would be cheaper to get a new LCD than run an old machine as a screen. In Australia, this would cost about 200-300 per annum to run.

Really?! That's interesting.

I'm in Melbourne (AU) and my figures don't quite match yours.

Take a fully 100% load (which it never does but let's assume worst case):
.150w / hr
9 hrs / day it's running
$.155 / kilowatt hour (is what I'm paying)
Works out to be
.15 x 9 x .155 = $0.21 / day
x 5 days per week that it runs = $1.05
x 52 weeks of the year $54.60 per annum to run.

...And that doesn't take into into account that I don't use my computer(s) 5 days per week, every week of the year.

I also did mention in my original post that it also runs as a communal file server and print server.

Cheers,

Ian.