A new modified version of the dock gnome extension by gcampax [link]
The dock is now set on bottom as default, which was the purpose of the modification, i.e. I modified it to get it on bottom and nothing else. Hope you find it as useful as I do!
It works on Gnome 3.4.x. Tested on Fedora 17.
-- How to change the icon size --
If you need to change the size of your icons, you use gsettings tool. For example, if you want to change to size 42 you type this in terminal:
gsettings --schemadir $HOMEemail@example.com/schemas set org.gnome.shell.extensions.dock size 42