Multi res aerial imagery

[Abe Gillespie]

Hey Everyone,

I was hoping I could get a few pointers about aerial imagery.  This is my setup:

Imagery format - MrSID
Resolutions - 100, 200, and 400

Is there a built-in way to handle multiple resolutions like this?  My
idea would be something to the effect of building a spatial index
(with gdaltindex) for all three resolutions into one shapefile.  Then
in the attribute table of the spatial index I would set a 100, 200,
and 400 value according to the appropriate layer on a field named
"res".  Finally, in the mapfile, I'd create one raster layer with
three different classes filtered according to CLASSITEM "res".  Each
class would in turn have the appropriate MAX and MIN scales.  Can this
be done?  If not, is there a way to accomplish this as a single layer?

Also, is there an authoritative place online where I can find
information on displaying MrSIDs in MapServer (tutorials /
references)?

As always, thanks for the help.
-Abe