Adium is an awesome application!
Other suggestions from my side would be to learn some of the keyboard shortcuts. There are some awesome features that allot of people do not know about.
Holding CTRL down and using the trackpad/wheel on mouse will allow you to instantly zoom in and out anywhere on the machine.
Pressing APPLE+SHIFT+4 will put the mouse in target mode and allow you to take a print screen of a selection and save it on your desktop.
In Safari press APPLE+I and Mail will open and embed the Whole Page as HTML into the mail. No more copying URLS!
These are just some of the few shortcuts.
Also another one would be the Right click! I don't like the one button on the Macbook's and Macbook Pro's so what you can do is Goto your Preferences and then to keyboard/Mouse and finally to the track pad. Select the option that allows Finger Tapping. Basically tab the trackpad with one finger and it counts as Left click and tap the trackpad with Two fingers will count as Right click.
Really cool feature. hope you enjoy your Macbook!