Can ayone tell me what a cock ring can do for me or my lover and what kind to get?

http://en.wikipedia.org/wiki/Cock_ring

I loke the "Lasso" style or the more dense rubber ones worn around both cock and balls. Definetly makes the veins pop out and makes the head a dark purplish red.
be carefull tnot to get the lasso style too tight. The wikipedia article is great and to me, very accurate.
Have fun!