This year, Lord Buddha's birthday is commemorated on May 24, though celebrations run over the course of a week. The main celebrations are at Lantau Island, the largest outlying island. (I have two pages of Lantau Islands photos, including the one on this post).
There's so much of interest to do in Hong Kong -- from Disney to the cable car to Lantau and the ferry to Macau to shopping and dining and Victoria Peak tram rides -- the list goes on and on. Two weeks is barely enough to scratch the surface, and there's something for every age group.
I'd go again myself, but work is keeping me close to home until summer, so someone please go on my behalf, and tell me how it went.