It was something right out of a sitcom: each guest at the weekend party asking the host, one right after another, for the wi-fi password, then heading into the office to squint at the router and bemoan the lost eyesight of our youth. But I just learned a completely different solution to this problem, and no, it’s not to make a poster of the password. It’s something more useful and more universal for the next new place you go.
It turns out that if someone else in the room already has the wi-fi password,and and iPhone or iPad, they can share it with you with one click. This is what popped up on a recent trip:
I did as suggested and the other phone presented an OK button and I’m in.
And/or you can do as my last host did, and purposely make a “Who’s on first?” password, such as “we don’t have a password.” I’ll leave it to you to imagine the conversation, or better, yet, try this at home!
Jane's Lessons Learned 
Works for iStuff (MacOS), but not for Android (45% of smartphones in US, 85% worldwide). Most wifi routers also support WPS, a small button on the router that enables you to hook up to the wifi network with your phone if you can find the button.
WPS stands for Wi-Fi Protected Setup. It is a wireless network security standard that tries to make connections between a router and wireless devices faster and easier. To use this method, you will normally need to enter the Wi-Fi connection screen on your phone, tap the menu button and select the WPS option you want to use from the menu that appears. iPads also support this, but apparently Apple doesn’t support it on iPhone. I think router vendors provide apps for iPhones to enable it, but clearly that makes it very hard to use, defeats the purpose.