I guess you could set up different install packages, Kevin, but I'm not
aware of a way to do that in one.

What I personally do is to install the front end only. This is the safer
choice anyway: it could be disastrous to overwrite an existing back end full
of data with a shiny new blank back end from the install disk.

So, in the installation instructions, we document how they need to choose a
location with full rights (including delete for the ldb) for all users, and
copy the back end data there. Then install the front end. Our startup code,
then looks for the data, and if not available pops up a File | Open dialog
so they can locate the front end. It sets the Connect property, and so they
don't get promped again unless the data file is moved or renamed.

There's a bit more to it if you are using Access security (MDW.)

What I do in my runtime installers is install the front end file and an
empty copy of the back end that has a different name.  This is
essentially a template for the back end.

When the front end is launched it refreshes the links to the back end.  
If it finds and existing back end file it links to that.  If not, it
creates one using the template file and links to that.  In this way the
app can be re-installed as many times as the user wants and their
existing data file is never over-written.

If I distribute a new version that has changes to the back end, then
variations on this same strategy can move all of the users existing data
into the new back end file.