This applescript snippet will change the away/available status of your Adium accounts. This is the only applescript I have found that has worked.
-- set to available
do_menu("Adium", "Status", "Available")
-- set to away
do_menu("Adium", "Status", "Away")
on do_menu(app_name, menu_name, menu_item)
try
-- bring the target application to the front
tell application app_name
activate
end tell
tell application "System Events"
tell process app_name
tell menu bar 1
tell menu bar item menu_name
tell menu menu_name
click menu item menu_item
end tell
end tell
end tell
end tell
end tell
return true
on error error_message
return false
end try
end do_menu