Oh, I was misreading it the post... for these preliminary phone interviews for jobs, the usual thing they're looking for is to find out things like:
* whether you're a psycho
* if you're really interested in the job or just grabbing at straws
* if your basic career plans fit their organization
* if they understand your resume correctly (definitely, you should have it on hand, but that goes without saying)
Usually, "screening" would be done by an HR person, so it's unlikely (albeit possible) that it's going to be highly skills-oriented. The basic idea is not to waste time flying you in for a real interview if you're obviously not going to work out (or take the job if it's offered). I find that chatty/friendly usually works pretty well with HR people. Expect a fair bit of seemingly stupid questions about things on your resume, like "I see you worked for Apple - is that a fruit company?" Sometimes those are tricks to see if you're faking stuff, and sometimes they arise from honest ignorance. Try to steer the HR guy toward things that pertain to what you're looking for, since there's a good chance you actually know more about the kind of job you're applying for than he does. When he goes to Dept. X to talk about you, he'll have notes, and you want him to be pointing at things Dept. X cares about.
Basic rule for all interviews: Figure out what they're trying to find out about you, and try to give it to them in a positive way.
I think the last time I did one educationally related (really for an internship), the interviewer forgot the time difference and called me at 2 AM, in German. "Hello... huh... wuh... Koennen Sie bitte das wiederholen?"