On/Off pulser (adjustable speed)

I'm in need of some help building an on/off pulser with a few adjustable speeds. It doesn't need to be perfect i just need a few settings. an example would be

0. off
1. once every 2 seconds
2. once every second
3. 2 times a second
4. 4 times a second
5. 8 times a second
6. 15 times a second
7. open circut

It would also be able to have different voltages and amps. Help anyone? I would really appreciate it...



Edit. As i hit create I thought of a strobe light... how do u make that kind of dial to were it speeds up and slows down the strobe. Thanks...

555 timer. Look at this