can you change your notification bar?

Are there replacements for the notification bar? I know some android devices have black bars. I am working on the droid so mines stock but are there replacemnts for the bar?

One side question: when I put a new folder on my desktop how do I rename it?

 

Okay so I kind of know what being rooted is but what does it mean exactly and how do I do it? Is it like a hack and will it screw anything up on my phone.?