This mod allows you to play as other models. If you have the mod installed and somebody uploaded a correct skin to his minecraft profile it will show for you. There is no need to install anything server side.
Features:
Animations:
The keys can be re configured in the Options -> Control menu
How to install:
For Minecraft 1.5.2
Other Versions:
Show Spoiler
For Minecraft 1.5.1
For 1.4.7/1.4.6
For Minecraft 1.4.5