"References available upon request." What do you think of this line on résumés?

It is useless and a waste of space. Potential employers will assume that references are always available and will be supplied after they ask for them, or there will not be a hiring offered. The current practice is to not insult a hiring authority with this phrase.

Rdrainer's answer is excellent!

So I would just add to that: That line is a no-brainer. Of course, references SHOULD be available upon request. But I have committed that mistake too after college.

Too tacky for my tastes. Include it with the resume already would ya.

HRs honestly have no time to be reading all these resumes with references. Make the resume as short as possible and if they happen to be interested, then you will be contacted and then the process shouldd begin, as it relates to reference.

If you do not give me any refs, I'm going to call the HR Dept. anyways. And since most will not give out more than basics, it will affect any decision I make

I think references available upon request is a clever ploy and it gives the job applicant more time to make himself / herself look better after a job interview. The interview tells the applicant what the employer is looking for. All the applicant has to do now is find references that will match the qualifications presented to him / her according to the potential employer.