Because my internet connection is very unstable at the moment, I'd like to use a small indicator applet for the Unity panel.
Since I'm connected through a WLAN/Wifi Router, I can see in the network-applet when the connection to the router is lost, but not when the router loses the connection to the Internet.
A Windows 7 computer of mine has this functionality. It shows a black exclamation mark on yellow ground if it can't "ping" a remote server.
I'm running Ubuntu 11.10 "Oneiric Ocelot" 64-Bit with Unity 3D.