Uhh not sure what you guys are talking about - I monitor the Maricopa regional wireless cooperative, which most of the police depts use right now with a digital trunking scanner just fine. Digital does not necessarily mean it's encrypted. Some specific channels are encrypted (Mesa PD), but there's tons of other freqs in use that are not encrypted - just simply digital voice.
Talkgroups and freqs can be found here:
http://www.radioreference.com/apps/db/?sid=2508
Maricopa County Trunked Radio System
Maricopa County operates a mixed-mode analog
and digital, APCO Project 16 800 MHz trunked radio network.
System users operating on digital talkgroups (as opposed to
analog talkgroups) use APCO Project 25 digital audio. This
network provides service for many agencies throughout the
metropolitan area, and is one of two large networks from
which various cities and other agencies may receive two-way
radio service (Regional Wireless Cooperative being the other
large network).
See also:
http://www.scannerstuff.com/swfd_Maricopa.htmThe scanner I use:
http://www.radioshack.com/product/index.jsp?productId=3348288 which essentially just a rebranded GRE PSR-600
http://www.greamerica.com/PSR-600.htmlI scored mine on eBay a couple years ago brand new for $225 shipped. You don't always see them that cheap, but if you pay attention you can get a deal on them. I wouldn't pay the $499 that Radio Shack wants, however, unless you're desperate. Usually RS puts them on sale once or twice a year.
BTW OP - visit the HAM forum for all things radio related - HAM radios, GMRS, scanners, etc. That's the best place to talk about this stuff and there's tons of scanner recommendation threads there
Oh and btw, if you do decide to get a digital trunking scanner of some sort, buy the programming software - you do NOT want to program talkgroups and freqs by hand for the new scanners. It's not simple like it used to be where you just punch in 40 freqs and hit scan
For the GRE PSR500/600 and Pro-197:
http://www.starrsoft.com/software/win500/default.asp