Have you ever wanted to keep an eye on what's happening with the hardware on your system using pop-up notifications? Well a little known extra to a very well known program called Growl could be just the ticket.
HardwareGrowler (HwG) comes packed with Growl in the "Extras" folder on the Growl disk image (as seen above) and can be installed just like any other application. Once up and running, HwG will notify you of any hardware changes to your system. If the MagSafe adapter gets yanked out or the power cuts out, HwG will tell you. If you plug in a USB drive or a network drive disconnects, HwG will let you know. In fact if anything changes behind the scenes on the hardware front HwG has you covered.
It's a nice simple application that has no user-configurable preferences to speak of, simply launch and you're ready to go. If you want to change the style or sounds associated with the notifications all you have to do is change it in the Growl Preference pane. HwG has a persistent dock icon, but you can get rid of manually with quick tweak.
So if you've been after a program to notify you if your MacBook gets accidentally unplugged, or you lose connection to a vital network or network drive, HardwareGrowler is a brilliant free little utility that you probably already have but just didn't know it.
Thanks to miguelpontes for the suggestion.