You must have seen high quality big banners on profiles of some of your friends, this is the new feature from Facebook called timeline banner. This allows users to view profile in timeline format where users see their activity in days, years, month format.
To add banner to your facebook profile just follow this link and read the instructions, it will as you to select a picture for background, upload the picture and get started with the facebook timeline banner.
Scroll down on your timeline and edit or remove any items you don’t want shown. Do that by holding your cursor over the upper right of an item you want to edit, and then click on the icon that looks like a pencil — it will have a label that reads Edit or Remove.
Make any changes or remove the items from the drop down list that you donot wish to see in your timeline or you can choose to delete the post altogether, or report it/mark it as spam..
You can also make the important thinks highlighted and bold. If you’d like to “feature” any of the posts, click on the star icon to the left of that pencil icon, and that item will be expanded all the way across the page, made larger for all your friends to see.
Visit here and click add timeline banner to your profile==>http://www.facebook.com/about/timeline