If you are an introvert or know of someone that is, what are things that you or that person can personally do to improve your/their networking capability? It is proven that networking has the highest relative contribution to successful management advancement.

It seems to me that social media is one way introverts can improve their networking capability. Having an account on a business-oriented site such as LinkedIn or on a recruiting site such as Monster publicizes their name and resume with little effort and no required social interaction. Similarly, having a Twitter or Instagram account can boost networking capabilities. Rather than "doing lunch" with someone, introverts can post and read posts from friends and colleagues from the anonymity of their computer, phone, or laptop. They can control who they communicate with and can even create a different identity.
Another possibility is to join a club such as Toastmasters, which meets specifically to practice public speaking, or any other type of club or class that improves interpersonal communication skills. Along the same lines, an introvert could improve his or her networking capability by joining any type of social group—even one composed of other introverts. You never know when you might make a business connection in a social setting.