Number Pads

I remember that I have read somewhere as to why there are two standards in how the numbers are positioned on numeric key pads, but I cannot for the life of me remember...

What am I talking about?
Well, take a look on the numeric keypad on your computer keyboard and then on your phone; on the computer keypad the numbers go 7, 8, 9; 4, 5, 6; 1, 2, 3; and 0. On the phone they go 1, 2, 3; 4, 5, 6; 7, 8, 9; and 0.

Now, why are there two standards, and why have not one of them taken over yet?

Computer-like devices:
Computer keyboards (from DEC VT52 to modern PCs)
Calculators

Phone-like devices:
ATM machine keypads
Pads for Bank errands via Internet
Port code devices (Code locks to enter the Server room or the building where you live)
Credit Card pads (when you pay in your local store)

I got some sort of answer when googling for examples of these two standards:
http://www.vintagecalculators.com/html/frequently_asked_questions.html#keyPads

It seems it's all Bell Labs' fault.

Still it doesn't explain why one standard hasn't taken over completely yet...