I came into work this morning to find out that one of our CISCO 2960s had died during the night, I haven't had a chance to figure out why, but I'm guessing a power spike killed it, and the surge protector it was using is useless. That said I've been thinking for a while about getting some small UPS units to power my remote switches. What would you use to power 1-2 Cisco 2960s for around an hour? Rack mountable is preferred.
The two Cisco 2960's (assuming non-POE with 48 ports) will pull 270 watts peak. At the minimum, you will need about 450-500VA in order to support that. However, with network closets, I always target a longer runtime since they may be connecting devices that still have input power.
With that in mind, if we target roughly 30 minutes of uptime you would be looking at 1000VA or so (it really depends on the battery size though).
I would recommend a double-conversion on-line UPS. This will clean up the power a lot more than a line-interactive UPS. I would advise toward APC's Smart-UPS® On-Line series of products.