For the most part yes, you can (and should) start looking now, but there may be special cases where an employer won't be able to consider hiring you until you've got a degree. Since you didn't mention any professional certification (architecture, law, medical practice, etc.) then I'm guessing that's not the case. My answer is also centered around the practices in the United States.
Typically, students just put (expected) next to a future (or current) year on resume/profiles to make this clear:
Bachelor of Whatever, Whatever University, 2012 (expected).
Getting your degree isn't really a magical date; you are going to see it through and you've already gained much of the experience. I would start looking now; some employers may even see that initiative as a positive. As with most things, employers are usually willing to try to work with issues that the candidate is honest about.