I'd say this depends on your reasons for being online. Are you using your blog for business, for fun? Want to market your blgo or just have fun online? If you are only wanting to have fun then continue the way you are doing now :) However I get the feeling that is not the case as you are asking this question so find out what you want to achieve during the year online and set up a plan.
A limit of the forum/twitter/facebook browsing can be necessary in some cases.
I have a list of things that I want and need to get done during the month and week and then daily so I can't fly around too much or I'll waste time.
I have to admit, the need for a time limit is imperative. I tend to go in cycles where I will spend a few days (and I mean every waking moment I can be glued to the laptop) browsing blogs, Facebook, Twitter, email etc... Then I'll go for awhile where my browsing is minimal and manageable. Prior to reading this, I created a bookmark folder titled "Daily Reading" - the sites in this folder are necessaries. Now if I can only hold myself to it! Best of luck.