I Think that I've been confusing an ImageView bitmap with a bitmap.
' saving the camera picture taken to a file
Dim out As OutputStream
out = File.OpenOutput(File.DirRootExternal, "myImage.jpg", False)
out.WriteBytes(Data, 0, Data.Length)
out.Close
dim imgPreview as ImageView
imgPreview.Initialize("")
imgPreview.Bitmap=RotateImage(LoadBitmap(File.DirRootExternal, "myImage.jpg"),90)
' now this rotated image, imgPreview.Bitmap, I would like to save to the original filename - "myImage.jpg"
Sorry for the confusion.