http://3dviewr.com is a web based COLLADA viewer for showcasing models. It supports textures (including normalmaps), showing wireframe and easy sharing for bbcode forums.
Here is a sample:
Click to view on 3dviewr.com
As a bonus the Java library it uses for parsing COLLADA (dae4j) has also been open sourced: dae4j COLLADA Java Library download | SourceForge.net