Pushover has an official plugin for Adium that lets you forward instant messages to your mobile devices that were received on your computer while you are away.
To get started, install the Adium plugin from the Adium Xtras site. Once the plugin is installed, open the Adium preferences and click on the Events tab.
Double click on “Message Received” to expand it and then click the “+” button at the bottom of the preferences window. If the Pushover plugin was correctly installed, you’ll see a “Forward to Pushover” entry in the “Action” drop down.
Enter your Pushover user key (viewable at pushover.net or from the Settings of the client on your phone) and optional device name.
To receive all messages while your account is away, check the “Away” option. If you are frequently away but only want to receive messages while you’re actually away from your computer and the screen saver has started, check the “Screen is locked” option.
You can apply this action to other types of events, such as only when certain contacts send messages.