Develop a Personality
I'm treading on dangerous ground with this one. Everyone sees the world from his own perspective. You might be saying, "I have a personality." However, technologists are particularly guilty of a personality that includes two contact-killing traits: introversion and arrogance.
The analytical nature of technology both draws and cultivates on a somewhat introspective mindset. This is particularly true for those in the programmer/analyst crowd.
Many technologists are perfectly happy at their terminal, designing and building their latest creation. Long periods of concentrated effort are required to be effective. For this reason, they come across as aloof.
If you are introverted, you will have to make an effort to ensure that you network adequately. It will be a stretch, but the payoff will be well worth it.
More dangerous, however, is an attitude of arrogance. This is less prevalent during economic downturns, but it is often so bad that it has become the source of cartoons, jokes, and incredibly, an entire character on Saturday Night Live.
Several years ago, the popular comedy program Saturday Night Live built an entire parody around a computer professional named Nick Burns. The "computer guy" skits might be over the top, but rarely does parody exist without reason. The perception among many nontechnical people is that "computer guys" or "gals" have a superiority complex and treat nontechnical users with the same disdain that Nick Burns, the Saturday Night Live computer guy, does.
If you are to effectively build a useful professional network, do not become or appear as a "Nick Burns."