I thought this was kinda cool

[UserLoser]

1. Key in the first three digits of your phone number (NOT the area code)
2. Multiply by 80
3. Add 1
4. Multiply by 250
5. Add the last 4 digits of your phone number
6. Add the last 4 digits of your phone number again
7. Subtract 250
8. Divide number by 2

[Explicit]

It is cool. 

[topaz]

...It goes in a mathematical loop.

[vuther.de]

Eh, it is "kinda" cool, waste of my time but bleh.

[dxoigmn]

Let x == first 3 digits of your phone number
Let y == last 4 digits of your phone number

((x*80+1)*250+y+y-250)/2
(20000*x+250+2y-250)/2
10000*x+y
xxxyyyy

[hismajesty]

pretty cool.

[Yoni]

Ass-crapfully lame.

[Joe[x86]]

Weak.

[vuther.de]

Got it from Ebaumsworld, eh?