this is a fantastic idea...  but would it  help to reinforce the crotch area?  that's the first place my hubby's jeans start to disentegrate....

I like this tip :-) thanks for the new idea

Would this work on jeans that's ripped in the back? I have the most perfect fitting jeans in the world, but the back's getting torn apart. :( 

Thats awesome... a repair I did for a friend whos jeans were are more hole than jean, I turned them inside out and cut a piece of fabric the same shape as the leg, its easiest if it only goes to the crotch, and then sew the fabric to the seam allowance , when you turn them back the right way you can't see the stiching and the fabric not only maintains your modesty warmth, but also holds the jeans together.