I have a few sources of news: Twitter, RSS, Facebook, and email. Occasionally app.net, but I haven't really gone through the trouble of building the proper community there, so not as much on that.
Your news sources may be similar, but could include Reddit, Digg, Slashdot, Monkeyfilter, Tumblr, or maybe even something weird like CNN. Whatever you're into and you check regularly.
I have this cycle I go through, and I suspect you do something similar: I check Facebook, then email, then Twitter, then my RSS feeds. Then maybe my RSS feeds, again, then Twitter, then Facebook, then email, or whatever. i finish one cycle, then I start over, maybe in the same order, maybe in a different order. If I'm really not paying attention, then I'll open the last app that I just had opened a moment ago.
Don't repeat your news cycle. If you need to check it again, check it later. Repeating the cycle over and over just takes up time you could be using to make your own thing. I've heard of some people who will check everything, then quit the apps for a set period of time (10 minutes, an hour, until tomorrow, whatever).
Don't let yourself get caught in the trap. The news will still be there when you get back (except if it's on Facebook, because there's no real way of knowing what they're going to show you from visit to visit, but even so: it's okay). Check once, do something of your own, then check back later in the day. You'll have more time to get stuff done, and then you'll have news of your own to report.