buy a small piece of leather to tuck behind the tear. Apply rubber cement or super glue to the patch and then tuck it behind the tear, re apply more glue where needed to keep the torn sides as closely togeather as possible, now put something heavy on it to dry and you should be good to go. FYI this patch job will come undone in leather dry cleaning solvent, but you can just re apply it.
Heidi, October 2008