Some of the products that you could use to make your hair straight without having to straighten or blow dry include straightening shampoo and conditioner. Other products include anti-frizz serum and hair spray. You could also use creams and waxes for smoothing the hair. Visit http://www.ehow.com/how_2139512_use-hair-products-straight-hair.html for more information.
There is a Garnier product called Blow Dry Perfector. It's a 2 or 3 step process, guarantees to keep your hair straight and smooth for 2 weeks! I've used it before and was very impressed. Check their web site for a tutorial, Costs about 12 bucks! Hope you'll like it!