I just tried a 12oz of my Al's Celebration Ale (see sig) yesterday, and it was definitely carbonated after ten days, but not quite ready yet. Since that was my first batch, I was mostly just very happy to discover that it came out good! Note that these are being carbonated using 2/3 cup* of corn sugar, and the temperature is pretty steadily about 70F. It was obvious that they needed more time to condition though, so be patient.
I will be waiting until at least 20 days before trying another 12oz. I just learned in this thread that bigger bottles take a bit longer, so I will wait a little longer on those.
*we weighed it, not measured, but we weighed out enough for TWO batches, and what I actually used was divided by eye, so it's probably not entirely precise, but it's pretty close.