Since this topic is being beat into submission as usual, I'll
add a pet peeve of a lot of controllers I know, myself included:

N1234: "airport in sight"
controller: "cleared visual approach"
N1234: "roger, we'll cancel IFR"

This happens daily, why? What is the point in reporting the airport
and a) not requesting the visual, if it's wanted, or, b) canceling in
the first transmission if the visual isn't wanted? Someone brought
up wasted transmissions, there's an example.

Speaking of wasted transmissions, and someone used the example
of five transmissions to get the Visual approach sequence rolling,
the controller who will be issuing the approach should on initial
call-in advise of what to expect. This should make it clearer
and what's expected of the pilot later. Example:
"N1234, expect visual runway 25, advise when you have atis Xray
and the airport in sight" (technically now I guess we have to say
the name of the airport and it's position - is it done? not often)
Anyway, that transmission sure shouldn't leave much doubt in
anyone's mind. It's also a good time if the pilot is requesting something
other than that.

Cruise Clearances: the reason it's not used much and rarely offered,
here anyway, is terrain and radio/radar coverage. It's basically
a block altitude from whatever you give away, to the ground, and
if it doesn't work out, back up to whatever altitude you assign. That's
one hell of a chunk of airspace to lock up. And you are never sure
how long you are really giving it away for as you may not hear the
aircraft cancel. Also things not used often or on a regular basis,
controllers get rusty on, let's be honest.
Contact Approaches: Read last sentence, just not requested enough
and pilots and controllers both get rusty on it. Example: had a guy
ask for one at an airport with no SIAP, another one asked for one
where the tower said they were totally IFR less than a mile visibility,
virtually impossible to accomplish. On the controller side, you'll see
the "standby" as they ask their supervisor if/how to do it.
Some observations,
Chris