Installing MOSS SP1
I'll save the steps that several others have already catalogued. Here is a decent blog that highlights the steps involved in deploying the service pack:
I received this message after installing the MOSS SP1: You must run setup to install new binary files for every server in your farm. If you have multiple servers in your farm, run setup and the configuration wizard on the other servers now, and then return to this server and click OK to continue.
What? Okay, here's what this means. You don't actually run the configuration wizard on every server first. Start with the server that hosts central admin and run the WSS 3.0 SP1 and MOSS sp1. Don't click OK. Go to each front end server and run the binaries on each of those servers. THEN come back and click OK which will start the configuration wizard on the first server. Go around and click OK on all the other servers after the Configuration Wizard completes.
It wouldn't hurt to perform and IISRESET, but I didn't do the reset and it seemed to function fine. I will test more tomorrow and update this post if I find anything useful.