Emacs on my Macbook Pro uses the "alt" key (the one to the left of the "cmd" key) to be the Alt (meta) key when doing things like Alt-Backspace to delete backwards by word. This is quite annoying for me as I naturally try and use the command key for this. To fix this put the following in your .emacs file.
(setq mac-command-modifier 'meta)
Bill Thompson has posted a thoughtful article over at the BBC about the changes that social networking is making to our standards of social interaction. He discusses his own tweeting and live-blogging at conferences, and then talks about the news updates that were tweeted by Tearah Moore during the Fort Hood incident.
I have recently been setting up my MacBook (running Leopard) to send email using the local email delivery system, i.e. Postfix. This means modifying the default installation to relay email through my ISP/email service - in my case; FastMail. I use FastMail because they have a nice secure email setup with both IMAP and SMTP access encrypted using SSL, but the instructions below will also work with Google Mail. The advantage of having your Apple Mac set up like this is that it enables command line scripts and various unix programs to send email. In my case, it allows me to use Mutt and Emacs as my email client.