The Wikipedia entry pedanticly insists this information is not verified, but I remember this too: "The original formula contained 1/3 beer which people used to believe made hair fuller and softer. Whether it was the beer which enhanced the fullness and softness of the hair or not, the shampoo did leave hair very soft and full, especially after blow drying."
You can still buy it at the Vermont Country Store, which also has Lemon Up and Gee, Your Hair Smells Terrific. But it's not made with beer, apparently, although it does have barley and hops. Also, I miss the old bottle.
Here's an interesting post from the guy who was the purchasing manager for the shampoo. The beer was Budweiser, but the company wouldn't let them reveal that because the beer had to be "denatured" so it wouldn't be taxed as alcohol, and also they weren't so high on the idea of beer being part of something poured on yout hear rather than consumed.
Here's an old commercial with Kim Basinger. BUT DON'T DRINK IT! Back then, all you needed to do was say that, however jokingly. Today you'd probably need an official warning label or something.