how hard is it to create your own sidebar, like google?

Hi all,

I don't know if this is the right place. But i am curious how hard it is to make a side bar like google.

In our case it will be a gimmick people could download from our website. Where the sidebar just gives the user the latest info.

Any tips, tutorials or links???

Got this link http://www.besttoolbars.net/

Kind regards