If you are a MobileMe user you can turn on iDisk Sync to create a way to share files between your Macs and your iDisk storage. Your iDisk is then treated like a normal local drive and automatically syncs with the server. Other Macs using iDisk Sync with your account will automatically stay in sync as well.
You can use Airport Utility to configure your Airport Extreme so you can access your Macs for file sharing and screen sharing. It involves both DHCP reservations and Port Forwarding. It also helps if you have a static IP address for your home Internet access.
Take a look at Back to My Mac, a feature of MobileMe that allows you to easily connect to your home Mac while away. You can share files and the screen. Back to My Mac will communicate with MobleMe so you can connect even if you are on a different network and have changing dynamic IP addresses.
Dropbox creates a folder on your drive that automatically syncs with a remote server. You can then access these files from your other Macs and iPhone, as well as share them with friends or everyone. It is a good way to keep a set of files in sync if you have more than one Mac.
If you have more than one Mac on your home network, you can share files between them by simply turning on file sharing and browsing to another Mac in the Finder. You can also add additional users and set up shared folders.
Learn about the new iTunes 9 Home Sharing feature. It lets you easily share and copy media from one computer to another from within iTunes. However, setup requires one or more iTunes accounts and the new features are simply shortcuts to what was already possible.
Learn how to use Bluetooth file sharing to send files from one Mac to another without a local network, wires or anything else. Handy for easily getting a file from one Mac to another in almost any situation.
Gary Rosenzweig looks at how to view music, photos and video from your Mac on your Wii using Wii Transfer. You can also use your Wii Remote with your Mac as a wireless mouse.
Gary Rosenzweig looks at how you can use your XBox 360 to view video and listen to music that is stored on your Mac using Connect360.
Gary Rosenzweig looks at how you can use your Mac to develop Web pages using the built-in Apache Web server and PHP.
Gary Rosenzweig takes a look at screen sharing in Leopard: how to set it up and some uses.
Gary Rosenzweig looks at how you can sync your iPod or iPhone to multiple computers using manual settings.