From the Arizona Motor Vehicle Department web site today, 9/4/06:
>>>>>>>>>QUOTE>>>>>>>>>>
State law requires that you obtain a driver license and registration immediately if any one of the following apply. If you:
* Work in Arizona (other than for seasonal agricultural work)
* Place children in school without paying the tuition rate of a nonresident
* Have a business with an office in Arizona, and that bases and operates vehicles in this state
* Obtain a state license or pay school tuition fees at the same rate as an Arizona resident
* Have a business that operates vehicles to transport goods or passengers within Arizona
* Remain in Arizona for a total of 7 months or more during any calendar year, regardless of your permanent residence
An "out-of-state student" enrolled with 7 or more semester hours is not considered a resident, even if employed.
Military personnel based in Arizona who qualify for exemption under the Soldiers and Sailors Relief Act are not considered Arizona residents.
<<<<<<<<END QUOTE<<<<<<<<<<
http://www.azdot.gov/mvd/azwelcome.asp
So, it looks like ANY work gets you residency by operation of law. Gasp. Consult your legal advisor to be sure.
Notice that the URL says "azwelcome"!
I really love Tucson -- Ive been here 4 years. Was in the Phoenix area about 40 years and wouldn't move back -- crowded, hot, smoggy, like a paved over little LA, with packed freeways and nasty politics. But, to each his or her own. When we retire in a couple years and buy our RV of our dreams, if we can, we are unlikely to want to do it in Arizona because of the amazing tax and license situation. Even here, in the Pima County area without City sales tax, I believe it is 7.6%. I don't know about RV license fees, but I wouldn't be surprised if they were many multiples of the $400 or so we pay on a 2005 Prius.