Question: Over the years, I've had to throw away a quite a few bits of computing equipment (and the like):

* Several ADSL routers with odd symptoms (losing wireless connections, losing wired connections, DHCP failures, DNS symptoms etc)
* Two PVRs spontaneously rebooting and corrupting themselves (despite the best efforts of the community to diagnose and help)
* One external hard disk still *claiming* to function, but corrupting data
* One hard disk as part of a NAS raid array "going bad" (as far as the NAS was concerned)

(This is in addition to various laptops and printers dying in ways unrelated to this question.)

Obviously it'll be impossible to tell for sure from such a small amount of information, but might these be related to power issues? I don't currently have a UPS for any of this equipment. Everything on surge-protected gang sockets, but there's nothing to smooth a power cut.

Is home UPS really viable and useful? I know there are some reasonably cheap UPSes on the market, but I don't know how useful they really are. I'm not interested in keeping my home network actually *running* during a power cut, but I'd like it to power down a bit more gracefully if the current situation is putting my hardware in jeopardy.

Answer: 
I give you a concrete example a few days old. 

My Macbook was directly connected to the power supply without UPS. I had an external display connected to it. I started my Macbook. My both display were blank. I could only heard the noise of my hardisks.

The solution to the problem was to take my Mac out of the direct supply. Both my displays get alive again.

It seems that the voltage was too high at the moment which caused me the problem.
I now have my Macbook in UPS - both displays work.

Other problems which I have had

1. My external harddisk got broken immediately as I connected it to the wall: it just corrupts data similarly as with you.
2. Three of my WiFi stations cannot get connections - they all are about one month old
3. My SCX-4300 printer seems to be broken after two weeks usage
4. A power adapter in my PC got broken after a year usage.
5. Two of UPSs are now broken after a year usage
6. My black Macbook's harddisk needed to be changed after one year.
7. One of my Al Macbooks do not start sometimes when it does not have UPS.

**Conclusion:** I recommend you to have UPS for your home equipment.
Not only is it useful and essential to protect your home computing equipment, but also if you have a home theater system. Basically, you'd rather the lower cost UPS buy it in the case of something happening.