I believe it does mean you're ovulating... right before you ovulate, your cervical mucus looks similar to egg-whites. It's a pretty good indicator that you ARE ovulating when it gets stringy like that... so now would be a definite good time to BD!!
Yeah, I agree with all of the above posters. The clear stringy cervical mucus indicates that you're in your most fertile phase (and just about to ovulate)! Time to get busy :-)