misc
Mac Icon Tutorial
This tutorial will show you how to download and use Halo Babies icons with your Instant Messenger client of choice.
Ctrl-click on the icon you want to download, and select "Download Image to Disk" (or some other variant).

- Set your new buddy icon in your preferred client. { iChat | AOL }
iChat
Click on the icon box in your buddy list.

Select "Edit Picture..." under the "Recent Pictures:" list.
Click "Choose..." in the "Buddy Picture" dialog box.

Find the icon you want to use and click "Open".

Click "Set" in the "Buddy Picture" dialog box.
AOL Instant Messenger
From the "AIM" menu, select "My Account Settings".

Click on the "Buddy Icon" tab.

Click on the "Open Icons Folder" button.
Now find your icon in the finder and copy it into the icons folder.

Back in the Account Settings dialog, select your icon from the "Custom Icons" section of the drop down menu.

Click "Save".
That's it, you're done! Well done!
Note: Only the AOL client supports animated buddy icons at the moment, iChat and others will only use the first frame of the icon as a static image, so choose your icons wisely if you use other clients.