ATM cards

A very useful and well-thought-out feature of most bank machines these days is that they wait for you to take your card out of the machine before dispensing the money.

This very simple feature makes it much harder for people in a hurry to forget to take their card from the machine! Otherwise people would collect the cash and walk away, forgetting the card completely (which would be an obvious security risk if anyone could get access to your PIN, not to mention being an inconveniece).

The only downside is that when you're exceptionally tired or stupid or in a hurry you can make a bit of a disaster out of the feature by taking your card when requested and then walking away before the machine has dispensed your money! (Yes I've done it before but thankfully there was someone in the queue behind me honest enough to point out my mistake).