But I was still getting calls from both nearby area codes, and from places I have no contacts, like Utah and Nebraska. Instead of answering, I called a few back on my landline. I found puzzled people that said they hadn't called me.

http://800notes.com/

I found this site 800notes, and while some of the numbers that called me are already notorious for spam or just plain harassment, others seem to be chosen at random by people with spoofing programs.

At present I only answer the cell phone when it is from a number I have already programmed into memory, meaning my clients, consultants, family, etc.

Similarly, I screen out a lot of the spam in the Cafe by looking first at posts recommended by people I trust.

The natural gas from shale deposits may last only about a year, which could amplify the intermittency risks.

Now as to what is preferable, I never expect to retire, but I have always worked at a draughting table or computer monitor. My brothers- and sister-in-law, who are my age, have already retired from the railroad with a host of physical complaints. Perhaps a better system would guide them into less physical jobs, but some people do retire because they can't work any more.