During that first iPhone demo they also had a portable cell tower (cell on wheels) just off-stage to mimic a better signal strength than it was capable of. NYTimes write-up on the whole thing is worth the read [0].

0.https://web.archive.org/web/20250310045704/https://www.nytim...

That _was_ worth it indeed--thanks :)

There was one demo where Steve Jobs told everyone to turn off their WiFi.