Meta refresh best answer ??

Hello, I am working on a site where people will be updating information in a database and should have up to date info. Now since HTTP is stateless the user will not know about any new information until they click on a link or hit a button on the page. My question is -- if I want to keep a user up to date about changes to any information they might want to know would it be best to create a hidden frame of some sort which does a mete-refresh to a page looking for updates, and if found display a java popup window with a small FYI ? If so would a meta-refresh of 3-5 seconds be to aggressive ? What about server load ? Is there a better way ? Hope I was clear, thanks. Michael.