I'm Sven Erik Tiberg newbee to this list, and working on a idea that's involves UDP transferes.
Basically it contains of human interacting to a 3D world ( X3D ) with a simulink ( matworks ) model runing on a separate server. States will be bidirectionell transfered by UDP diagrams over Internet.
I'v created some simulink modules that forces the model to run in pseudo-RT-mode and transfering states by UDP in format ( 10  times %f\t% ).  And some X3D worlds that needs to be route'd to this UDP state tranferes by twisted-python scripts.
Any hints and tips? Or as x-mas wish: code snipps.
PS: Present reading "The Twisted Documantation" may 25 2006. Like the reactor concept. 
Sven-Erik Tiberg 
Dept of IT.
Lulea Univ of Techn.