Random Riddle: 9-15-2014

If you never give me a break,
You will find I may never again wake.

I am optimistic on one side,
I can be short, fat, tall, or wide.

Sometimes you have to wait long for me to get ready,
Just hold on for a few hours and be steady.

I can help you get around to the market or mall,
and even help you make a call.

What am I?