1. Glass Pill:
Download
2. Ubuntu Panel:
Download
3. HUD:
Download
4. Froyo:
Download
5. Rounded Glass:
Download
Usage
To install Plank in Ubuntu, use the commands below (this will add the Plank/Docky testing PPA):
sudo add-apt-repository ppa:ricotz/docky
sudo apt-get update
sudo apt-get install plank
The above PPA is available for Ubuntu Oneiric, Natty and Maverick.
To use a theme, make a backup of the original Plank theme under ~/.config/plank/theme/ and then extract the downloaded theme into this folder (~/.config/plank/theme/), replacing the already existing files. Note: ~/.config/ is a hidden folder in your home directory so press CTRL + H to see it.
Themes thanks to Cassidy James; via elementaryositdev