Okay... I've done this checkin:
http://github.com/dpp/liftweb/commit/be575ea2ceb6510c17b905e12b2d9b22db892d37It adds a heartbeat function to LiftRules for Comet-enabled containers (read Jetty). There's a modification to the examples code to demonstrate it.
On my local box, "it worked fine".
Looking for feedback on (1) if it gets the job done for Daniel & Co. and (2) how we can make it more general so that we can bring it forward to Lift 2.0.