We reported in a recent news roundup that smartphone adoption is on the rise. This could be a boon for mobile local search adoption, given hardware features (keypad, larger screen, etc.) that are more conducive to some MoLo applications (see our recent Advisory on the subject).
There are many more factors driving (or inhibiting) mainstream MoLo adoption, such as GPS ubiquity, but smartphone adoption will come into play. This San Jose Mercury News article goes into more detail on the falling prices and improving technology that are driving the recent rise in adoption.