1.   The lactation rooms, behind an unmarked door, restrict access by requiring users to punch in security codes, which are changed twice a year.

2.   Using the list, a user need only punch a button to be connected.

3.   In a trial, the company let users punch in data about themselves, making it available to compatible singles within range.

4.   Instead of sitting in front of a personal computer, a user could punch the screen of a hand-held gadget en route to work.