I need to be able to send asynchronous events from a servlet to an applet. The applet would then 
display that some activity has happened on the server side. It  needs to be pretty reliable, and can't 
have significant time lag. What is the best way of accomplishing this communication?

 - I have looked at sockets and would run into firewall related issues.

 - I can try RMI - but have been getting concerned about the overhead. If some one has examples for 
this, it would be appreciated. 

 - Can I do polling - setup URLConnection from applet side and send events from servlet side and wait 
until I get data on the ObjectInputStream?  Can I continue to send data on this connection 
asynchronously from Servlet?  Any examples?  

 Can someone point if these are valid concerns? And if so, what is the best solution. Performance is not 
a key issue.