After trying again and again to get OpenSim running on CentOS 5 64bits, and persistently failing at it, I finally surrendered and installed in on Windows XP. I had an old Dell PC standing idly in a corner; downloading OpenSim and installing it was a breeze. Configuring MySQL wasn't much of an issue either; only a network issue and some tricky configurations in OpenSim.ini gave me some headaches. In the end, I got it up and running in a few hours - not bad. The kids are going to be happy tomorrow!