I wrote last time about the latest developments to my Views Auto-Refresh module, which periodically refreshes a Views page, either by reloading the whole view, or by incrementally inserting new items only. It's a useful tool for activity streams and other Twitter-like, real-time lists.
Still, I had a nagging feeling that my code was endangering the server. Consider this: every 15 seconds, each connected browser invokes a full Drupal bootstrap plus a full View render, just to ask the server if there are new items.
Imagine you are creating an activity stream for your site. You'd like to use Views because it gives you all the power you need to query items and style them on the page - all in time for your 11am nap. However, the resulting page is static and users have to keep refreshing it manually to see updates. In 2011, that's just uncool.
That's why I created Views Auto-Refresh, a Views Hacks sub-module that implements an auto-refreshing mechanism that integrates right into Views 2 or 3.