Thanks for that Gaieus I'll give it a go.
I would really prefer something that will import textures as well anyone know of one that will do that?

I'm wanting to use the program RSP 3D PDF which only runs using Sketchup files. The problem is that I want to load 3D models I have created from actual 3D object. These models are currently in .scn and .obj formats but I will need to convert them into .skp(sketchup) format to run them in this program.

Does anyone know of a program or converter which exists that can convert .obj files into .skp? If not what file formats are the best suited to be converted into .skp formate and where would I need to go to convert them?