[squid-users] upgrade but leave earlier version running?

[J Webster]

Is there a way to install the new version of squid and leave 2.6 running 
and then swpa them over once I am sure everything in verison 3 is 
running on the server ok?
I don;t believe CentOS 5.8 has anything in the repos above 2.6 so is 
there a way I can use yum without installing from source and compiling?