Collada for google earth

I have a .3ds file that is not compatible with google earth. How can I convert that to Collada(.dae) file? OR Is there a tool to create my own 3D models with .dae extension ?
Thanks a bunch

If you want to place a model in Google Earth, download SketchUp, import your .3d file and export to GE.

If you want to convert a .3d file to .dae, then download the FBX Converter (free, from Autodesk). With that you can convert a 3d file to FBX file and then, the FBX file to .dae