Which UPS?
 

Not the shipping company but rather an uninterrupted power supply.

Looking for one for the computer and one for the AV closet.

1 - Computer, monitor, router

1 - Receiver, tivo unit, 46" LCD

APC seems to fit the bill but they make a hundred of them?

Looking to keep the bill below $150 or so for both.

Do any of them shut down the computer if you are not around as opposed to the battery simply draining down?

Some of the APC units come with software you can load into the computer. I think you need to run a separate USB cable from the UPS to the computer. When the power goes out, the UPS signals the software, which in turn does a clean shut-down of the computer.

Not sure how well it works, or how it handles unanswered "Do you want to save?" dialog boxes. I was supposed to load my software, but never got 'round to it.

I expected to see UPS chicks when I opened this.

You really need to add up the wattage from all the devices and go from there.

I use UPSsssssssss behind a couple of lights and I used to have one that powered my stereo/T.V., but then I upgraded and killed the UPS.

You will need a pretty big unit to power a receiver and T.V. $150.- for both units won't cut it.

Dave's absolutely right on this. With my current UPS, it used to power everything just fine for several minutes when the power went out. Since I re-built my PC using a 1000 watt power supply (up from 500), every time there's a minor flicker, it shuts down immediately...just like it was unplugged.
I need a beefier UPS.

Start here, and I believe APC is the industry standard as far as UPS's are concerned.