Back in 1999 and 2000, while Jason and I were getting started on "Consternate" - I was doing my homework by watching LOTS of horror films. The original "When a Stranger Calls" was recommended to me, and I checked it out. While it was fiarly creepy at times, it wasn't the best production value. Thus, a remake - like this one - doesn't have a whole lot to live up to.
The film has ONE good thing going for it: It is suspenseful, most of the time. (When you're not yelling at her about what she's doing wrong)
The film has one MAJOR thing going WRONG for it: Lack of story. Lots of suspense with little payoff, and a cheap (and obvious) ending.
Aside from that, it's just plain average. I've seen A LOT worse, but there's so much better stuff out there.
If you're on a date, and you want a chick all over your arm, this is the right movie. If you're looking for something that's actually "good" - Check out "Match Point".