it is a safe thing to do it stores power so don't leave it plugged in, otherwise it might shorten the battery life :O

It's ok to do in short spans, but if you keep your laptop or even desktop on for weeks you can run into some basic processing errors.

THE SHORT ANSWER: It's totally safe to put your desktop in standby.

THE LONG ANSWER: I always use standby. It wakes up quicker because it doesn't need to avcess the boot files or the registry all over again. I only shut off my desktop when there's a thunder storm. I pull the plug so it won't get zapped. we get blackouts here very often. I only restart when installing requires it or when antivirus updates. Aside from a storm, if I'm out of town for a few days (ie. going to Furpocalypse), it turned off and unplugged from the wall.

-hugs-y