I just returned home from flying for the first time since before 9/11

[Sgent]

8. Pre-check is the way to go if you fly even semi-regularly

you probably got it because you were on the same reservation as your friend (who has it and has status). You can sign up at the TSA website and then have to go to an airport for an interview. TSA can also randomly bump people to pre-check for whatever reason (in this case same reservation).

Global entry is a little more expensive ($100 vs $85 / 4 years) but gives you TSA pre-check plus the advantage of a pre-check like experience when going through customs and immigration.

Global entry requirements are stricter -- although we don't know by how much cause they won't say. In addition, an interview for global entry can take months where a TSA pre-check can be done the same day if your at an airport with a desk.