Well here's one way of using them to your advantage:
Step 1: Get as many to call you as possible
This is super easy. Post a job advert somwhere, almost anywhere. Your own website, LinkedIn, IT jobs sites, Job Centre Plus, on a particular CMS's job board. This is definitely a case of build it and they will come. After you get a job advert out, your phne will most likley start to ring itself off the hook.
Step 2: Get them to send you CV's
They will be dying to send you CV's. So I normally make it very, very clear that we are not using recruitment consultants, but still agree to them sending CV's and stuff. They will all send you thier contact details, and some will send you CV's. The CV's are normally anonomised, having names of people and companies removed.
Step 3: Track down the candidate
Despite the CV being anonomised, you can often still track them down using LinkedIn, Facebook and Google. Read the CV through carefully, try to identify any names, places, past or present companies, schools, universities. It could all help. Plus look for any reference numbers, these often contain initials or partial names.
- LinkedIn
Searches on LinkedIn can be a little mysterious, I'm not sure if they restrict the results sometimes. But try searching on any of the information you've found from the CV. You can should be able to try keywords, location, present company, past companies, school, universities, first and last name.
I've found that maybe 50% of the time I can find the person.
Note: You may have to pay for InMails in order to contact the person via LinkedIn. But, you may also be abler to find out extra info about them to find other ways of contacting them. - Google
Take a sentence from the CV that looks unique. Search for it on Google in quotes to match it exactly. I found that sentences that are a list of skills are less effective. Try sentences that are desciptive of the persons attitude or personlaity. These descriptions are often used on LinkedIn profiles or peronal portfolio websites, or some techincal sites and forums.
Of course if you know thier name or any of the other details above, search for combinations of these with text excerpts. - Facebook
Can be useful if you know the persons name, but haven't had any luck on LinkedIn or Google.
Disclaimer
There are a few potential legal and moral issues with doing this. In theory they may claim that by reading the CV or by agreeing to receive them, you are agreeing to thier terms. Also you might consider this dishonest.
On th eother hand, so many recruitment consultants are far more dishonest with they're infalted claims of being a 'specialist' in recruiting candidates with certain skills. Or in the number of candidates they have currently looking for the vacancy you're advertising (sometimes they have them but they all live miles away, or are only contracters when you want permanent, etc).
I've event had one that took the copy from my advert, removed anything that could identify our company, then ran the advert themselves to poach the candidates. Dirty.
Anyway, if you do use this technique successully , let me know.
More on IT recruitment: Best IT Job Sites, How To Interview a Web Programmer