Thanks! I didn't know about Safari's plugins, and I didn't have specific criticisms of it -- other than the crashing bug with drove me nuts at one point -- because I haven't worked with it as much as I have Firefox. Usually it just hangs out in the background somewhere running Pandora and occasionally being a testbed for a site. (However, it just took forever to shut down...)

GlimmerBlocker looks great, I'm trying it out now.