Interesting to read this thread.
In case you don't know, I am known as the father of the FastPass Guide a couple of decades ago, and featured in places like the Unofficial Guide to Disneyland.
I have used probably the first type of FastPass like thing in an Theme/Amusement park, and that was Universal Studios Hollywood, where they realized that it was getting too busy to force everyone onto a Tram first thing, and had to send some to the rest of the park with a return time. It was an expensive decision, as they original set up allowed staffing to start later for the "after tram" part of the park, but greatly increased capacity.
I have done the old Cedar Point thing, where you got in line for an 11 AM hand stamp to avoid most of the wait in line later in the day. They had latex hand stamps that had the ride and return time, you were lucky to get 2 and maybe 3 with inside knowledge. But it was once a day, and everyone in the group had to be in line, usually the line for the stamp would be 30 minutes to an hour.
And I also remember when I could use my Ralphs Grocery Frequent Shopper to get a Disneyland FastPass. (so basically unlimited), so they started to improve the system, and then my Annual Passes from other parks would work. (Since the admission system barcodes are an industry system, and not exclusive to Disney). Disney finally went to "real time" where a pass HAD to be scanned at the front gate before being valid that day, which stopped that issue. Then the amount of connected/unconnected machines, and how they worked.
Also, the policies of using FP's after the stated return time, and how that is no longer allowed.
But then, I also love the Lo-Q that Six Flags, Dollywood,
LEGOLAND and others use. This is a pager like device, where you can just search and request a return time anywhere in the park, with limits into what you can request at one time, usually one ride and one show at a time. And if you want to change it, there is no issues. They also have a water park version where you wear it on your wrist.
https://en.wikipedia.org/wiki/Accesso
Also, some water park systems allow a payment option for food and merchandise. You can set a certain dollar amount, or just attach a credit card to the band. No need to carry a wallet/money around.
You still have some other systems, like what Universal and Cedar Fair (Knott's) uses, which is a lanyard/wristband that is scanned and allows front of the line access without a return time being assigned for an extra fee.
Things change, and now Disney is looking at adding additional costs to use FastPass, such as a requirement to stay at a Disney Hotel for better access.
But as a local, a lot has changed over the last few decades, and I use them less often now.. though they did come in handy when my wife and I created a new World Record that hasn't been beat yet.
http://web.archive.org/web/20070301165523/http://www.miceage.com/guest/gu070306a.htm
https://darkbeer.smugmug.com/Theme-Parks-2006-Photos/11-Parks-11-Roller-Coasters/