Michael has made his rather nice ServerBar utility available.
If you have a Mac and you manage Unix-type machines (including other Macs, of course), this might be for you. It only really does one thing, but it does it well – it shows you the load on your remote machines – and it gives you a convenient shortcut (by clicking on the graph) to a terminal on any machine. If you know what SSH is, this might be of interest.
Recommended.