ping-based network monitoring GUI?

[Count László de Almásy]

Greetings,

I'm in need of a simple GUI application that "monitors" a range of
hosts using ping and reports on their status by changing the panel
color for that host (i.e, green for pingable, red for unreachable). 

Does anyone know of any existing opensource program that does this?
Preferably Python so I can extend it easily.

If not, what tools would you recommend I write this kind of app in?
Ping doesn't seem to be supported by Python out of the box, and the
modules I've looked at seem sketchy.  I looked at Expect, and see
there's a Pexpect module available.  Once I have the core
functionality nailed down, I'll probably wrap it with Tkinter.

Thanks for any advice.