Reply #1: zombie dogs

[calmblueocean]

Here's a link I remember from last year where scientists "froze" a series of dogs by replacing their blood with a freezing saline solution. The dogs' heart and brain functions, among others, were stopped and the dogs were legally dead. 3 hours later, the saline solution is replaced with warm blood and the dogs were resuscitated.

http://news.com.com/2061-11204_3-5777094.html

I don't know how long a dog or a person could be in this frozen state and still be revived, but it seems reasonable to think that further research along these lines could extend the time one could safely stay frozen indefinitely.