In a BEA Viscount when I was 7 or so, went to the cockpit and despite all the controls and switches, I thought the cupholders to stop the cups of tea sloshing around was the best thing since sliced bread.
Today after take-off, in the 757 I go to get my half drunk cup of coffee from my cupholder and get drips of spilt coffee on my left leg thanks to the take off acceleration.
Thank Gawd we wear black trousers !