I really dont have the time to read tweets during the day.
Currently, I am following 600 of the coolest, smartest, most interesting people on the interwebs. People like Eline, Nalden, Renn, Ernst-Jan, Tijs, Boris, Alexander and Jourik. Together they generate shitloads of awesomeness.
I read their tweets on moments otherwise lost on boredom. While traveling, waiting on a bus, while on the train, while waiting for coffee and while waiting for my PC to reboot. And always on my Blackberry, using Ubertwitter.
Whenever I find an interesting tweet, I favorite it (HT @Scobelizer for the tip). I subscribed to the RSS feed of my favorites in Google Reader, so they end up in my RSS routine (I read y RSS feeds every morning).
In this flow, I dont lose time reading tweets during the day, but postpone the action until they show up in my morning routine. This routine also helps me to find the real gems in the people I follow, the list of people I favorite most.