One company even helps college freshman move into their campus dorms to establish a relationship with them for later recruiting. There's no simple answer, but one of the ways to combat the problem is to utilize all the resources you have. In recruiting entry level candidates for openings, target colleges. Attending a career fair once a year just isn't enough in today's market. You must network with career centers, college professors, clubs, and associations.
Career centers vary in what services they offer.
Some will only put your position posting in a binder in the office where students must come in and look for it. Others offer a full line of services that include posting, job lines, online resume access, hotlinking to home pages, and resume referral services. If you take the time to get to know the people in the career centers, they are a solid resource in referring candidates to your company - but you have to take the time to get to know them and share information. If you are speaking to a class of freshman, coach them on how to prepare for their career search and get them thinking about the industry your company does business in or how to evaluate opportunities in the market. If you are speaking to a class of graduating seniors, tailor your presentation to what they have learned and to what they are looking for in their career search.