Don't have a lot of time? Think you missed something? These mash-ups update dynamically!
No doubt, you've used one of these at one time or another.
Take another look if you haven't looked lately!
Popurls - Added a lot of new content in the past three or four months.
Techmeme - How many people are writing about the same thing? It's a 'good thing'.
SEOMash - Top of the heap updates for the SEO / SEM crowd