What do you do when a recruiter calls you? What about when you get an unsolicited e-mail from a recruiter you've never met? Although most out-of-work job seekers jump at the chance to talk to a recruiter, these same people often avoid building these relationships before they're in need.
Regardless of your job search status, recruiters can help broaden your search.
First, take their call. Even if you're at work. Take their call. Of course, you can simply say that you can't talk at that moment, take down their contact information and call them back. Even if you're not looking right now, there is no good reason to turn away an introduction to a recruiter. If it's via e-mail, you can still call the recruiter.
Offer a referral. If the position is not what you're looking for, or you're simply not looking for a change, offer to refer someone you know. Make a qualified referral and that recruiter will likely never forget you. That doesn't mean you have to give up your co-worker's phone number and e-mail address. Talk to your contact and give them the recruiter's information. Follow up with the recruiter in a few days and see if your referral made contact.
Too many people ignore recruiters as they would any other salesperson (and in a future post, I'll try and convince you why even that is foolish). Get to know recruiters in your industry before you need them.