I've applied for jobs a few times and this has always been a problem. Now that I've been out of college for a while it's even more of a problem. I don't have anyone from college that would even remember me. I can't use my current coworkers because I don't want my current employer to know I'm leaving until I have a new job lined up. I don't keep in touch with old coworkers. I don't do anything outside of work as far as volunteering or anything. I know I'm not supposed to use friends or family. Who is even left after that? The only people I have the contact info for are friends, family, and my current boss.
Recent graduates seeking employment in their field of study should always have their department chair write a recommendation. Having other professors write recommendations helps as well.
Unfortunately I'm not applying for a job in the field I went to college for and I never actually graduated. I went to college for comp sci because I liked programming as a hobby. About half way through college I got a gig to fix some software and I realized that if I had to do that all day I would jump off a bridge. So I went and taught myself refrigeration. Very little of what I studied in college actually applies to my new field.
Put them as a reference anyway. Your qualifications speak for themselves; the references aren't there to show you know the subject, they're there to talk about you as a person. If they can say you're hard-working, enthusiastic, have good attention to detail, or whatever, then it doesn't matter so much what task or subject they're talking about, it's those attributes and attitudes that make you attractive to an employer.