I have a PDF file of that book. It was okay. Kevin sure babytalked us all through it and repeated himself a lot. But I suppose that was for the benefit of the retarded corporate people buying the book.
As far as how I cover my tracks - I usually don't. I'm lazy. I just call their toll-free numbers direct. They rarely notice my number. I've been called back before, mostly by Verizon Wireless and T-Mobile. But that's only when they suspect me of being fake. In most cases I just get the info and that's the end of it. Not like it's illegal. Yet. And sometimes it's interesting and/or beneficial to get the phone number that shows up on your caller ID when they call you back.
A couple years ago I called Bell in Canada to get some info. I ended up getting half of the account info before the guy got suspicious of me. Soon afterwards, my cell phone starts ringing and it's a Canadian number. I ignore it. He calls back and I ignore it again. This time he leaves a message where he lectures me for nearly a minute about how I shouldn't be doing that. Then later that evening I get a call from a completely different phone number in Canada. It's the same Bell guy again and he leaves another message for me, lecturing me and sounding very sad that he had to deal with me earlier in the day. I checked the number he was calling from and it was his HOME! The Bell guy called me from home, just to have a talk with me. Poor guy probably lost some sleep over the incident.
Another incident from a few years ago is when a security guy from Verizon GTE called me. I talked to him and he told me that someone from my number was calling up their offices and pretending to work there to get information. I said, "Oh goodness gracious! It must be somebody from my work using my cell phone without my permission!" He warned me to keep a better eye on my cell phone because if it keeps happening, he'd have to do something about it. Like maybe tell me to cut it out again, probably.
Oh yeah, I do have one thing that thwarts phone companies when they call me back. My Vonage line is forwarded to a prepaid calling card number. So when anyone calls me back, they get a message that says, "You are returning a call to a prepaid calling card..." With Vonage, you can set the number of seconds before forwarding occurs. So mine is set for 5 seconds. This means i still get the caller ID of the phone company calling me back. But if I don't pick up, they think whoever called them was calling from a prepaid calling card.