They can tell you about the company or industry and answer specific questions. They also can sometimes network to higher-ups within the company. In addition to colleges and alumni, try any relevant professional organization. Many local business or professional groups make membership lists available to members. You can always meet new people at meetings and conferences.
Some professional groups operate resume exchanges.
This is done by the printing industry in New York City and by some state CPA sociesties. Some college placement offices operate similar services. A candidate who is a member or alumnus can provide copies of his or her resume that the sponsoring group will then circulate or make available to interested employers. There is no charge to the candidate. Job hunting is not fun in good times or bad.