Apple has released two updates that enable users running either Leopard or Snow Leopard to take advantage of the multi-touch capabilities in the new Magic Mouse (see "Apple Releases Magic Mouse, New Remote, Souped-Up Base Stations," 20 October 2009). Apple notes that users running Leopard must have version 10.5.8 installed, and that Momentum scrolling is not available. Users running Snow Leopard must have version 10.6.1 installed. Both updates are available via Software Update or the Apple Support Downloads page. (Free, 36.22/63.92 MB)
Fun Way to Send Attachments in Mail
If you're working in a file that you want to attach to a message in Apple Mail, you can transfer the file to Mail easily: From the title bar of the file's window, drag the little proxy icon to Mail's icon on the Dock. Your Mac will make Mail the active application and open a new outgoing message, with the file attached.
(If your icon won't drag, the file probably isn't saved.)