Do you leave your components on 24/7?

Lately I've been leaving my components on all the time, on the assumption that a) they'll be ready when I want to listen, and b) the on/off cycle ages the equipment (tubes, anyway) faster than leaving everything on. Is the latter a reasonable assumption?

03-01-11: Mitch2
The manufacturers of my SS disc player and SS preamps say to leave them on all the time (one of the preamps doesn't even have an on/off switch).
i used to have a krell cd player, and while it had an on/off switch, it was really an on/standby switch. what i did not like was that krell components tend to consume a fair amount of power while in standby. when the cd player was in standby it was warm. i currently have a wadia cd player and while it has an on/off switch it is located in the rear of the unit because the intention is that the unit should be left on all the time. the wadia cd player is fairly cool, which suggests to me that it is not consuming much power; if it were warm, i would definitely reach in the back to turn it off when i wasn't using it.

my attitude about it is that if the power dissipation is like that of a night light, i won't make such a big deal over leaving it on; after all, displays on microwaves and ovens consume energy; but when the energy consumption is enough to light a room, then that's a bit too much to leave such a component on 24/7.

one of my criticisms of the audiophile biz is that it seems to often promote profligate waste for little (or effectively no) benefit...
I have a Wadia 861 thats been on 24/7 for well over 5 years.Not one problem.

Wadia recommends that it stay powered up for several reasons.As they put it..."The unit will remain thermally stable for less stress and wear on internal circuitry and for best sound quality as well."

Who am I to urgue with them.
Both of my preamps (2 rooms) are designed with on/off switches, which control power to other devices plugged into them(I do not do this). The active circuitry was designed to always be on. I also leave my power amps on all the time, as well as my dacs. My transports, tuners and other sources go on as I listen. I find that amps sound better when on 24/7 as well as dacs. I do not use tubes, even though I own horns....
Also wanted to mention I will play some music for 5/10 minutes to "open the system up" before I seriously sit and listen.
I turn everything off except a Rel sub that's designed to be left on (no on/off switch anyway, and it's plugged into a different outlet...I unplug it when gone for days) as not much is happening until it gets a signal. Otherwise, having had gear work for MANY years without any issues from switching, I feel that more is likely to go wrong when electrons are running around my gear without adult supervision. I did have a hybrid guitar amp die from being on for a week once. I think it makes my gear appreciate me and perhaps look forward to seeing me as I can use my "godlike" powers to give it life. Am I insecure?