My plan was to have a library that modelled a web page as an asynchronous Erlang process. Other Erlang processes can send it messages using the standard Erlang constructs and the clients browser would process these messages. I put a proof of concept here.
This model of usage is becoming more and more popular evidenced by the number of Ajax based chat applications as well as the new 'Comet' term. The latest release of the Java based DWR library has added functoinality similar to the message passing example mentioned above.