Thanks Erel,
The general idea works. Because I have a Droid X2, the path wasn't
File.DirRootExternal exactly but rather was another path:
root = "/mnt"
folder = "sdcard-ext"
subfolder = "appfolder"
sdf=root & "/" & folder & "/" & subfolder & "/"
WebView1.LoadUrl("file://" & File.Combine(sdf, "slideshow-example.html"))
This construction works perfectly and my Jquery driven slideshow works as intended from sdcard-ext.
It appears that DirRootExternal = "/mnt/sdcard/" which is an internal sdcard at least on the droid X2
One other small gotcha is if you don't change the USB setting to PC and leave it set to sdcard, the program won't find the sdcard-ext.
Thanks Again.
Tom B