I have a Mac network, which has five Mac's. Right now, they are individually getting software updates. Is there a way to download the patches/security updates in a single place (repository) and point all machines to this location?
Personally, I have tools like Monolingual and Onyx, but are there tools you could recommend that affect the performance of the Operating System positively? Tweaks would be nice. Links and pointers, would be really appreciated.
I've read about Time machine, is there a way to backup all machines to a network drive using this tool?
You'll need a Snow Leopard Server to do this, but it has a Software Update Server that you can use. It mirrors the updates from apple.com and makes them available on your network. If you want, you can manually choose which updates to mirror and approve. There's freeware tools for setting the Software Update server on your clients if you don't want to get into managing them with the server itself.
What are you expecting to find? It's not as if there's some hidden busy loops that Apple left in the OS for enthusiastic tweakers to find and comment out. :-) If you're having a particular problem (e.g. battery life problems from applications forcing use of the discrete graphics in current MBPs), then a particular tool might help, but there's no general "performance tweaks" to take on OS X. Also, be careful with tools like Monolingual. I've heard of them causing updates to fail when you alter Apple-supplied binaries. The same thing could happen with 3rd party software if their updaters don't account for things like this.
This is another area where Mac OS X Server is useful.