A friend purchased a package of Betel Nut. It was a foil-sealed pouch that came with a dosage scoop. We each chewed one scoop apiece.
The nut is initially hard, like cat litter. The particular brand he purchased was flavored with clove and cinnamon, and thus tasted like Christmas potpourri.
We held the quid in our cheeks at the beginning of watching Final Fantasy: The Spirits Within. Near the middle of the movie, the nut was soft enough to actively chew, but had lost its cinnamon flavor.
Near the very end of the movie, I found myself chewing frantically. I experienced a definite stimulation, although it was cool and mild, nothing at all like caffeine or pseudoephedrine. However, by this time the flavor was so bitter and offensive that I had to spit it out and rinse my mouth with water.
It is hard to say how potent the stimulation was, although I did end up staying awake all night. However, I am prone to insomnia if I have any stimulants past noon. I didn't feel exhausted until around 2 PM the next day. One pack of cigarettes aided in this.
Overall, I'd say the experience was pleasant. However, the partially-chewed nut resembled something that had come out of the south end of a cat, with a comparable flavor.