Wifi is now in almost all company-owned Motel 6 locations ($2.99 a night) and in quite a few franchise locations (often free).
In 2007 I found that more than 80% of places I stayed - hostels, campgrounds, small motels - had Wifi, and only once was I asked to pay, $3 per night. That was at the hostel in Taos NM.
Now so dependent on my computer, it is the first thing I ask. :)