This should be as easy as making a copy of the LAYOUTS folder  in the 60
hive (let's say you call the copied folder myLAYOUTS). Have the host
change the _layouts virtual directory in your IIS Web Site to point to
the myLAYOUTS folder and all site definitions, admin pages, etc. will be
unique to you Virtual Server.

Maybe you can even convince the host to give  you FTP access  to the
myLAYOUTS folder.

I still have two questions.

First, in IIS, the _layouts virtual directory points to:

..\60\Template\Layouts

A new

..\60\Template\Layouts folder  won't give  me a new
..\60\Template\1033\SPS\default.aspx

Second, in IIS, when I try to put  a virtual directory under my
second portal  and call it "_layouts" IIS errors "alias does not
have a unique  name" presumably because there's already a virtual
directory with the same name even though it listed under a different
web site.

The question  still remains: if I have two portals  on one server,
how do I make it so one's home page is different from the other?

You need to create  your two portals  and then go into C:\Program
File\Common Files\Microsoft Shared\Web Server Extensions\60\template\
and copy and past the LAYOUTS folder  and IMAGES folder. Rename them
to something else such as PORTAL1_LAYOUTS etc etc.

Open up IIS admin and expand the portal  website, open the properteis
for the _LAYOUTS folder and change the current home directory path to
the newley copied folders, do the same for the IMAGES virtual
directory.

Once done you can then edit the CSS Styles, Images for either of the
portals without affecting the other one. If this doens't make sense
let me know.

Let me take a stab at answering your questions.

Your first statement is absolutely correct. The \Layouts directory is the root directory linked when SP is extended to the IIS Web site. Everything above that directory in the hive is considered global. For your second statement, you can’t add the virtual directory and call it _layouts, but rather change the pointer of the _layouts directory to the new _layouts location  after extending SP.

Ok, now it's getting a liitle clearer.

There's an IIS snap-in bug that "hides" the virtual directories in
websites:

(http://support.microsoft.com/?id=308179 applies to MSCM in IIS 5.1
but this is what happened to me in SPS and IIS 6.0) I closed the
IIS admin tool and went through computer management | services | IIS
and I could see the existing virtual directory _layouts. I changed
the virtual directory's home folder  to ..\60\Template\MyLayouts

I understand the part about copying ..\60\Template\layouts as ..\60
\Template\MyLayouts.

I understand that I can customize anything in those files
exclusively for my second portal.

But you're saying that the ..\60\Template\1033\.. folders
are "Global".

That would mean all the portals  on a server  use the same ..\60
\template\1033\sps\default.aspx

That means you can make them different only by using the custom.css
and the other items you can get to in the UI. I presume you can
also rewrite the classes in .css code in content editor web parts.

Last question... If I modify the file  in FrontPage by navigating to
the website, as opposed to the OS, wouldn't I be able to make the
new portal  home page look different there?

By using <shiver>

FrontPage

</shiver> you can indeed make the page exactly like you want it, except then it is unghosted. My thought is to never do anything with FP but rather utilize css and template changes to achieve the desired look and feel. Now, this will limit you somewhat in how much customizing you can do, but the ramifications of doing it any other way make it, IMHO anyway, not worth it. You are correct about everything else though (class rewrites and changes through the CEWP).