unfortunately the htc dock bar cannot be edited. if you want something more customizable you would have to root your phone or try another launcher (easier option) some of the more popualr launchers are ADW, GO and Launcherpro. All i believe have free versions to try out. i personally use launcherpro plus i like the scrollable dock (can put 15 items in the dock) i havent played much with ADW or GO so I am not sure if they have that feature, I also like LPP cause of its sense like widgets (btw the widgets for launcherpro are only available with the paid version). The LPP friends widget looks oddly similar to the HTC Friend stream widget. Also LPP now has skins available on the market for the widgets.