Actually Taurine + caffeine = jitters
BUT
Taurine also functions as a neuroregulator and nerve cell growth factor.
It promotes a calming effect by inhibiting the release of norepinephrine and acetylcholine, and stimulating the release of GABA
Taurine increases the production of serotonin and melatonin by stimulating the activity of N-acetyltransferase, resulting in normalization of sleep and nerve functioning.
(Chapman, G.W. and Greenwood, C.E. Taurine in Nutrition and Brain Development. Nutri Res 1988;8:955-68.)
....though I have never tried Taurine for falling asleep