[plug] diff scripting question

[psteege at tpg.com.au]

I have two directory structures.  A working one and an archive.
I wanted to see which files had changed between builds.
I tried doing "diff -r -s directory1 directory2 > diffs_file.txt
This worked but it also did a diff on executable and data files which 
made the diffs_file.txt gigantic.

I am trying to create a script that will search down a directory, 
from where I am currently located and find all non-executable files 
(type text or command script..etc) and diff them against their same 
name in another directory.
The part I am having trouble with is how I can determine which ones 
are not data files.
I know I can use the "file" command to determine type, but is there 
another linux command that identifies them?