Security Update 2011-006 (Snow Leopard and Snow Leopard Server)
To bring the security fixes from Mac OS X 10.7.2 Lion back to 10.6 Snow Leopard, Apple has released Security Update 2011-006 (Snow Leopard) and Security Update 2011-006 (Snow Leopard Server). The security vulnerabilities addressed are many and varied, with numerous affected components. Plus, Apple has updated a number of root SSL/TLS certificates. We recommend these updates for anyone still running Snow Leopard; it’s easiest to let Software Update install the correct version for you. (Free, 136.28 MB for Snow Leopard / 144.91 MB for Snow Leopard Server)
Oiks, just realized haven't updated since 10.6.1 - can I go straight to this, or do I need to update incrementally?
Absolutely - Apple is very good about this. You want the Mac OS X 10.6.8 Combo Update 1.1, and once you've installed that, you can install Security Update 2011-006.
I think if you run Software Update, it will just give you the right stuff automatically.
Awesome - thanks very much for your reply!