hybridcon is a very simple utility to let UNIXen talk to Hybrid cable/microwave modems over UDP. It can show you all the information that CCMInfo can, plus more. You can even change lots of stuff. Once connected, using the Hybrid configuration console is much like configuring a router over a serial line: one line commands let you do everything that the modem allows.
Version 1.1 is available at http://www.zigamorph.net/hybridcon/files/.
If you're any good at GNOME or KDE programming, it would be fairly trivial to implement a 'tray' status viewer that is equivelent to CCMinfo (or even the graphically elite CCMLink).