A beautiful image Pixero. Love it.
On the other hand, the basic principles of modeling remained the same.
What has changed is the huge development of render engines and the ability to support huge meshes.
Having this 3d digital sculpting. (ZB, MB, 3DC, Sculptris, Blender)
Most importantly the tremendous power of modern CPUs and the excellent freeware around.
Back in 1996... when a quadra 700 and in 1997 (mac G3) where more than enough to run the excellent macromedia freehand. I was able to construct a 24 pages brochure, full of quality scans. If I recollect right, it was more flexible than Indesign or QExpress are today.
In 1998 when the best ever Illustrator (V8.01) was able to run a 2dCAD plugin.

A masterpiece
About texturing techniques:
My advice is to start involving in blender - cycles render engine.
Have a look on the box-blended-mapping method for instance. No UVs, excellent solution for this case.
http://blenderartists.org/forum/showthread.php?256634-Another-gargoyle-a-recent-cycles-test

http://forums.sketchucation.com/viewtopic.php?f=323&t=33448
But triangulation remains.
Obj supports ngons, actually.
Same ridiculous problem with newer blender builds. Though blender supports ngons (bmesh builds). Still the obj exporter converts them to tris.
Zbrush is an app that does not support ngons. However, the importer will ask for the method to triangulate them, it even has a converter to quads as possible.

@pete
We lost the first one.
Maybe football is more forgiving.
I don't think so.

@unknownuser said:

However if Germany wins tomorrow you will play them next.

Funny, I thought we play with them today.
Oh may, this is the UEFA-euro thread. Apologies.

Blender.
You don't have to learn how to use it.
Just download it. Hit preferences panel / addons, activate all imports exports .
Now import the stl, do nothing in 3d view, export as 3ds.

I suppose this stl is less than 64 k faces. If it's more than this, don't expect SU to support it.
(if it's more than 64 k, you could start learning blender a bit. Just select the mesh, go to object modifiers panel and ask for decimation.)

There may be other excellent apps around for conversion but not for decimation as well, neither for UV mapping, rendering etc etc.

http://www.sketchupartists.org/tutorials/sketchup-and-blender/blender-to-sketchup-a-workaround-for-texturing-organic-shapes/

But it's old now, a blender 2.49b and SU workflow.
Not many changed, just the blender UI, a little.
Why not updating it? Because I learned a lot about blender and I don't use SU much any more.
Basically I import in blender only. It's the cycles render engine, you see. And the ability to set up huge scenes using 100k trees as instances
But exporting a model to SU gives you an opportunity to easily share it with SU users. As skp.

@unknownuser said:

I just spent the last few hrs reading your SU/BLENDER workflow, fantastic, i even tested it and i had unbelievable results, its like the missing link iv being in search for, this is simply brilliant, cheers for the workflow

Thank you.
Where? On SketchUp artists? If yes, it's an old one using blender 2.49b. Some things have changed, but the basic principles exist.

@unknownuser said:

Yeah, I was wondering how Athens, Greece got so detailed in such a short time in Google Earth

I don't think they did it this way.

Lucky artist contest isn't a contest, really.

@iichiversii
On my reply, there is a second part. This is the most important.
SU produces terrible topology sometimes. Mostly because of the bad habit lot of SU users have to not take attention on this. How could they? They don't know what they're doing, most of the time. To cut an arc opening on a rectangular base is very easy. Can you realize what bad topology this may means?
Import a SU obj in zbrush or blender. Subdivide once. Enjoy...

DAE is your worst option.
OBJ is a good one, use TIG's free exporter, not the internal Pro one.
Shame on you if not already tried it
http://forums.sketchucation.com/viewtopic.php?f=323&t=33448

3ds, avoid it, some limitation makes your work complicated... Though the only option for SU imports.

But, but, it's not the format the only issue.
To have all faces looking outside (normals) is crucial. I haven't found any ruby that can do the work (not having blueish faces, white only) You have to do it manually.
Another issue may be the internal faces (non manifolds), Here, another fine, difficult to find these days- ruby.
http://forums.sketchucation.com/download/file.php?id=86061

SU forgives all these but with what cost... half performance on OGL when double faces are rendered.

You may find this thread (mine LOL) interesting, some things have been discussed already. You may download the tree sample (skp file) though it is imported as 3ds from blender. The only format SU can import decently
http://forums.sketchucation.com/viewtopic.php?f=179&t=44345

In other words...
"If you want to develop desktop applications—anything that runs at the command line or on the conventional Windows desktop that remains a fully supported, integral, essential part of Windows 8—you'll have two options: stick with the current Visual C++ 2010 Express and Visual C# 2010 Express products, or pay about $400-500 for Visual Studio 11 Professional. A second version, Visual Studio 11 Express for Web, will be able to produce HTML and JavaScript websites, and nothing more."

http://arstechnica.com/information-technology/2012/05/no-cost-desktop-software-development-is-dead-on-windows-8/?comments=1&start=80#comments-bar

Yeah LOL
BTW, the use of the term DPI isn't accurate here. We should use PPI instead.

And you still don't understand what you see. I can feel your pain. I lived with this pain for six months. But I may be stupid.
The truth is that what I learned all these months is much more than what SU can provide to me.
During these months I also learned Zbrush and 3dcoat. And everything between them. Do you have any idea what this means?
All these because of my love to this 3d world.

The problem with quotes is that it is hard to verify their authenticity.
Not Abraham this time, just me.

Wonderful brochures Richard.
I wonder, have you tried to edit SU vector PDF exports in Illustrator?

@unknownuser said:

He he, If you haven't already done so, I strongly recommend reading the "Dirk Gently - holistic detective" books by Douglas Adams.
One of the running jokes is the sofa that Dirk has to squeeze past every time he leaves his flat - it is jammed in just the kind of position you describe.

One of my favorite Douglas Adams books.

Thank you Tom.
Wow!

@unknownuser said:

Apparently, the German government now wants to tax the pensions they pay to Belgian citizens who were forced to do hard labor in Nazi Germany. The tax is retroactive, too (starting from 2005).

Un-bloody-believable. Whoever came up with this, needs a beating.

Is this true?
Please provide some more information.

Beautiful work Ken
As always.