My lovely wife Rowan and I watched Cellular last night, and we have quite a divergence of opinion. I really enjoyed it, and gave it four stars out of five. She gave it two stars (out of how many, I didn't ask). She gave it a letter grade of C+, I believe. She thought it was a highly improbable plot, a point I stipulated, but I found it enjoyable, nonetheless.
We both enjoyed one of the extras on the DVD: a half-hour documentary into the LAPD Rampart corruption scandal of the late 90s. It only tangentially fits into the theme of the feature, but it's riveting.