Scanner listener and licensed HAM checking in.
Up here in MN we've got a mix of APCO-25 (Motorola Digital system) and conventional agencies.
My "home county" has been analog since I started scanning and is currently in the middle of switching over, all the rest of my haunts are in areas that are digital already.
Cordless phones are illegal to monitor due to the Electronic Communication Privacy Act. (Interestingly, it was legal to monitor cordless phones until the ECPA was ammended sometime in the mid 90's. Ditto for cellphones.) Most cordless (and cells) are no longer susceptible to "average joe" monitoring... they utilize digital spread spectrum and are by that very nature encrypted against casual eavesdropping. Plus, most scanners will not even approach the frequencies that new cordless phones operate on (2.4 GHz, 4.8GHz, 5.2GHz and above...).
Legally, you're free to listen to just about anything you want to at home as long as you don't repeat what you've heard. The largest exception is, you cannot listen to anthing that is encrypted or a cordless or cellular phone.
On the road, laws very from state to state. Some states allow mobile scanning without too much grief, others require permits from either the state or county you plan on monitoring while mobile (Minnesota is one of these), and some seem to say it's altogether verboten. your milage may vary.
One interesting loophole is that most state laws allow for licensed HAM radio operators to carry a scanner in their vehicle*. (Again, Minnesota is one of these.) There are a few states that disallow mobile scanners altogether,
BUT a fairly recent federal premtion of state law exists due to a decision by the FCC. As it's written, a state may not restrict a HAM from carrying a radio capable of recieving police band communication as long as that radios primary function is to exist as a tranciever in Amateur Radio bands. The FCC decision/Federal Law makes no mention of, nor specific exception for a seperate police scanner.
*
There are cops out there with a "I do not enforce the law, I AM the law!" additude everywhere you go, sadly... the best remedy is to find a copy of your state law. Print it. Laminate it and a copy of your HAM radio license. Have a good lawyer on speed dial. This may be the only thing to save you the headache of an overzealous and ignorant (or thug with a badge type) cop trying to force compliance with a non-existant law or trying to force compliance with their "respect mah AUTHOR-IT-TAY" mindset.
If push comes to shove and you end up in court the fact that you've got a copy of the law, your license, and a lawyer in tow should at least help you win a criminal case; if you can prove that Officer Porcine had a copy of the law in hand, plus your license and other relevant paperwork, it may work in your favor should you decide to file civil suit as well.
[/side-rant]
Some of the most interesting things I've personally heard were the radio chatter surrounding the Interstate 35 Bridge collapse, the Mall of America's complete shutdown and search due to an armed abductor thought to be hiding in it somewhere, a couple of apartment/townhome fires, high speed chases and robberies.
Having a scanner in my truck has on more than one occasion helped me get off the highway after a traffic accident had both lanes of the freeway tied up, it has helped me find a spot to pull off the road to clear the way for a fire truck to get to a call, and it has helped me find the best spot to pull
way off the road to get out of the way of/watch a high speed police chase go by.
Aviation can be fun to listen to, railroads can be okay if you know the lingo, taxi cabs can be fun, and so can towing companys. If/when you get mobile with your radio, it can be fun to listen to drive thru window frequencies at McDonalds, Burger King and other fast food places.
For fast food it's not so much the ordering, but what some of the little punks say about the customers when they think no one can hear them. (*Racial comments, comments about sexual orientation, about physical attributes, and personality traits of their "regulars"... I've heard it all, and this was in just one night of listening. Just one more reason I hate Culvers.)
One other oddball thing that's fun to listen to is the remote cueing frequency for your local live news reporters. Comments about the studio politics, comments about the good looking (*smokin hot in some cases) news anchors and questions about whether they'd been working out lately, etc...
Anyway, there are a couple websites worth checking out...
Radio Reference - A nationwide database of scanner frequencies/ trucnking codes, etc... updated almost weekly.
FCC Databse Search - Exactly what it sounds like.