[fryke]

I've reduced my machine park in the past. Currently, I _only_ actively use my MacBook (see sig). I've got a PowerMacintosh 9500 collecting dust in the attic (it's got Rhapsody DR2 or Mac OS X Server 1.x and Mac OS 8.6 on it) plus my Macintosh Colour Classic, which I occasionally power up to see whether it still runs. Then I usually write a short story on it (because it still runs, obviously), copy that to a floppy, put that floppy into a Sony Vaio external USB floppy drive and copy it to my MacBook. Wow. Lot of trouble to stay compatible. (It's got no network card...)

Generally, I'd say you can save quite some space and energy if you have a newer machine. Keeping one machine up to date is okay, doing that for three or four machines can be too much hassle. In my "best" times, I was actively using a PowerMac 9500 (mentioned above), the Colour Classic (also mentioned above), my TiBook 500, my eMate 300 and an AMD K6/200 running Rhapsody DR2. I can tell you it's more quiet to just use the MacBook for everything.