HTTP accelerator mode - fallback options

Is there a way to have squid fallback to various sites in accelerator
mode if a primary server is unavailable?

I've read the docs and the FAQ and they talk about using a single squid
to acclerate multiple sites, but I really only want to accelerate one
site, just with squid being smart enough to try a different machine if
the first one is unavailable or the entity is not found.

ie: you request file.gif. squid tries to get it from
server1.gamespot.com, and if server1 is down or returns a 404 squid
immediately then tries server2.gamespot.com.

-- 
Jon Drukman                                            jsd@gamespot.com
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Plan: Eat right, exercise regularly, die anyway.