Old boss used to say "if it all went right for the customers, we wouldn't make any money."
I get customers ask me how long it will take to set trusses on a house. I ask them how hard they're going to work, because they won't be waiting on me. I've had similar size houses take 3 hours with one crew, take 8-10 with a different crew. I usually won't schedule something else for a operator, on a day he goes to set trusses with a new crew.
I also kind of gave up on trying to book more than two jobs for one crane in a day. Every time I try for three jobs in a day, I'm on the phone with two customers, explaining why I'm late. Usually its because some truck driver is lost, or thinks he can cover the 350 miles he has yet to travel, in 3 hours.
But none of this is about how I kill time on a job when there's nothing to do. Usually I'm getting on the phone, bugging my wife/secretary, planning the next couple days of work. Sometimes I'll check in with the other operators, but I try to leave them alone, they'll call me if they need me. Then I try to make it a habit to just look the crane over for leaks, maintaince items. I never grease on a job site, unless its there for a really long time.
Judging from the time your posts were made, I'd say your spending extra time reading and posting on Heavy Equipment forums, not a bad use of time at all.