Twitter is worthwhile. A lot of news seems to break there faster than ESPN update messages, or any other method I've seen. There are some good FF writers who tweet or retweet insightful articles too. I can kill a couple hours bouncing around the twittersphere.
Here's a quick rundown of who I follow:
Adam Schefter, @AdamSchefter
Jason La Canfora, NFL Network guy, @JasonLaCanfora
Evan Silva, Rotoworld, @evansilva
Chet Gresham, writer at football.razzball.com, @Chetrazzball
Jim Day, goaheadscore.com, @Fantasytaz
Michael Lombardi, another NFL network writer, @michaelombardi
Brad Evans, Yahoo! FF writer, @YahooNoise
Keep in mind that a couple of these guys aren't solely football writers. Some will tweet about baseball, basketball, even life.