Cheung Sha beach which is about a 20 minute bus ride away has windsurfing and canoe rentals.
Swim
At silvermine beach in mui wo or at any of the other beaches around the island.
Hikers
May wish to try the 70-km lantau trail, which does loops around the island. the full route would take several days but is divided into a dozen stages, some of which take less than an hour.
BBQ
Have a BBQ on the beach
Citygate Outlet
(http://www.citygateoutlet...) - located right next to tung chung mtr station, the citygate is a rare outlet mall with tonnes of mid-priced brands, some of them being adidas, esprit, giordano, levi's, nike, quiksilver and timberland. prices are generally lower, but the greatest savings are to be had during the end of season sales.
discovery bay
Special events and festivals:
Dragonboat races around May/June (http://www.youtube.com/wa...)
Halloween Festival October
Multi-Cultural Festival usually in November
Others:
Golf at the Discovery Bay Golf Club, a 27-hole golf course open primarily to members, but also guests during weekdays
Boating at the Discovery Bay Marina Club
Hiking a number of hiking trails lead to other parts of Lantau Island