Memetrackers or blog aggregators provide a quick glance of what is happening in the blogosphere, often these memetrackers index the stories fast before they made it to Google and other sites. BetaSignal.com is a memetracker launched recently that tracks science, technolgy, environment and space news.
Techmeme is good for technology and web related stuff, if you want a bit of science along with tech BetaSignal provides a nice alternative. BetaSignal tracks the popular blogs and news sites focused on science and technology. The front page lists the top 10 popular items, you can browse more clusters using the navigation that way you never miss any important news.
You can browser river of the news from new items. Tags will allow you to see all the items it indexed before.
BetaSignal has an API for developers who want to make use of the data for creating mashups. API supports RSS, JSON and XML formats.
If you are looking for a more general memetracker than techmeme, Betasignal is a good alternative. Check out our own memetracker indimeme.com for Indian blogs