OK...
Some people have trouble following my other tutorial... Well, here is a new, much clearer tutorial with pictures!
AND NOW... I include blender!
OK! Fasten your seatbelts!!!
Requirements:
Sketchup 6
Blender 2.49
Unity
STEP 1:
Determine your version. In the end, it must, MUST be a
sketchup 6 file. However, if you have sketchup 7, I can fix that. When
you go to save your sketchup 7 model file, save it as a sketchup 6 file
instead!
STEP 2:
Get that file into sketchup 6! Look for the file that you just
saved. Open it in sketchup 6. Hey, if you have a mac, but no sketchup
6, I have a little present for you!
Ok, open that file! Now, you must save it as a google earth 4 file
(.kmz) NOTE IT MUST BE GOOGLE EARTH 4. Go to edit/export/3d model...
Name your file and chose the Google Earth 4 file format.
Export the file. Export it to a folder where you can easily find
it. Now, find the file and change the file extension from .kmz to .zip
STEP 3:
Now, Double click the .zip and unzip it into a folder! This folder
contains Materials, Models, and a doc.kml file. Kml file is useless,
don't worry about it.
You will need to know the location of this folder to import it into blender. Now, let's open blender.
STEP 4:
Open blender. NOTE: 2.49 is needed for a successful Unity import. Please use BLENDER 2.49
Import the .dae file from your newly unzipped folder.
Go to file/import/collada 1.4 (.dae)
Select the file...
Now, select "import and close"!

STEP 5:
Export your file! Select File/export/ 3D studio (.3ds). You may choose Collada 1.4 (.dae), or wavefront (.obj), but I prefer .3ds.
Remember to name the file!
Now, let's export! Choose the desired file directory to export to.
STEP 6:
Locate your new .3ds file and import to unity!
Go into finder and search for your file name (I will search for "box")
Now that you have found it, note it's location. Remember it and open unity. Create a new project if desired.
Now, Import the file into unity. Go to assets/import new asset
Select the recently exported .3ds file!
Note that the file is now in the project box in unity.
STEP 7:
Put your object into the scene! Click the file and drag it right into the scene.
Finish! You have now completed the Sketchup -> Blender -> Unity tutorial!
Tutorial courtesy of GTR34