Depending on what business you are in, I think it is very important to attend conferences and business meetings. Even online blogging gurus attend conferences for face-to-face contact.
Actually, I think for those of us who work online full time, it is probably more important than ever to get out in public and meet others. Whether the local Chamber of Commerce meeting, a meet and great in your niche, or a major national convention, the importance of shaking hands and talking to others is of utmost importance, IMO.