I finally figured it out...took forever, but I found it.
First of all, its called a 1,2 methide shift, not methyl as I previously thought.
And, in terms of 1° and 2° alcohol dehydrations, if possible it WILL occur, and its possible either always or 99% of the time.
Theres no 1,3 methide or 1,3 hydride shift, but there is a 1,2 hydride shift.
"Molecular rearrangements of this type frequently accompany Sn1 reactions, especially in highly ionizing, non-nucleophilic solvents such as formic acid and acetic acid. As a rule of thumb, rearrangements will occur whenever they can produce carbocations of equal or greater stability"
(taken from: http://www.usm.maine.edu/~newton/Chy...s/default.html)
Looks like you and I both need to brush up on the O-chem.
PS: chemistry kills my inner child