LinkedIn to open service to high school students LinkedIn Corp. will soon open up its online professional networking service to high school students as part of an effort to help steer their collegiate careers.Effective Sept. 12, the new minimum age to create a LinkedIn account will range from 13 years old to 16 years old in most countries where LinkedIn operates. LinkedIn is lowering its age requirements so high school students can tap into a new feature, called "University Pages," designed to help them learn more about colleges around the world and connect undergraduates with alumni. About 200 universities have already set up pages on LinkedIn, and the company said thousands of more schools will be given access to the new feature during the next few weeks. By lowering its age requirements, LinkedIn will open up new growth opportunities that could help the company widen its usage and bring in more revenue. It doesn't cost money...