I was in Antigua last fall -- the most hopping beach area is Dickenson's Bay right by the Rex Halcyon and Sandals resorts. You can rent jet skis, etc there pretty cheap. See a guy named Mouse at the Rex's Surf Sport rentals area, he'll take care of you. Especially if you say Michelle and Amy from L.A. sent you...
If you have a whole day there--I recommend taking an Island Safari --for $50 they will drive you all over this gorgeous island in a land rover--you see the rainforest, beaches on the pacific and caribbean sides and its a total riot.
If you are there in the evening--check out Lashings down at the end of Runaway Beach. Much much fun!
Sunday nights -- steel band and bbq at Shirley Heights is a must for locals and tourists alike. Its crazy and so much fun!
[This message has been edited by amycat412 (edited March 23, 2001).]