if i'm going to be gone for more than 2 nights.

In my case, I leave my desktop on because I'm very disorganised, and shutting down would mean closing windows that I still need to refer to. I might have a page open for several days before I get around to completing whatever action that was intended to remind me of. So yeah, indirectly, it does make me more money....... :error

Some say that the mechanical stress of repeatedly spinning up and down could also lead to premature failure.

Is that really even practical with modern OS's that cache and do background stuff which requires drive I/O? I see my XP box HD light flickering every now and then, even when I haven't typed anything on it for hours. That would spin up the drive just to read or write a few sectors.

i just googled and read a couple of sites, and from my perusal it looks like the general feeling on this is that it doesnt save wear and tear on your machine really nowadays, but a while ago it did.

also, it said that you can save power by hibernating and sleeping your computer, and by of course, shutting it off...

so you do save energy, and the energy spike it uses to turn on doesnt outweigh keeping it turned off the entire night, or weekend.

i read or heard somewhere that switching it off every day is better than leave it run for a long period..

Whenever I have to put it in my laptop bag so I can change locations.

Once or twice a week

everyday! :)

the PC need to rest too.

Every night for me :)