Keyboard Extras

Chatting to a friend today about some recent changes to keyboard behaviour on a Mac led me to discover an iOS-like feature that operates under Yosemite - hold down on various keys to give access to accents, etc.(maybe it's been there for a while?).
This led me to check whether my iPhone carrying friend (owner since 3GS) was aware of the press & hold iOS keyboard options... he wasn't - how about you?
To access various URL suffixes in Mail or Safari: hold on the full stop key and slide your finger to the one you want, then release.
To use letter/character accents and special characters: hold on the desired base character (vowels, etc), slide and release.
A different currency symbol: hold on that $ key.