Ok guys
Try this version

commands:

gconftool -s /apps/osso/hildon-home/task-shortcuts-size -t int XX ---> XX = icon size

gconftool -s /apps/osso/hildon-home/task-shortcuts-back -t int X ---> X icon background (0=no, 1=yes)

gconftool -s /apps/osso/hildon-home/task-bookmarks-size -t int XX ---> bookmarks size (width size, the rest is autosized)

Have fun


EDIT: If you decrease bookmarks size you will loss the bookmarks labels (think that's because it doesn't fit in space), sorry for this...