A keel stabilizes a boat allowing it to go in a straight line (one direction).

The Samsung Straight Talk phone has a menu allowing incoming calls to be blocked. It can be found as an option when the call comes in. An application can also be downloaded to do this.

We see the sun because of the light it shines and the light from it, travelling in straight lines, is going into our eyes allowing us to see it.

When erect I assume? They are all different. From barely raised to tight against the belly. Most will be more or less straight out allowing for weight but some are going to point straight up.

You don't want to bend the pins