notifications.sh

gwd()
{
    $*
    growlnotify "${1} is done" -m '…' -s
}

bwd()
{
    $*
    printf \\a
}

nwd()
{
    $*
    terminal-notifier -message "\`${1}\` is done" -activate com.apple.Terminal -sender com.apple.Terminal
}

Use this like so:

nwd <some long-running shell task>

Then you get a Notification Center alert when it completes. If you click on it, Terminal activates.

Growl when done, beep when done, and notify when done.