I've found the following tours and classes are still free: Duk Ling Ride (although by April 1, 2008, all rides will have a minimum of 50 HKD fee), Tai Chi Class, Architecture Walk, Cantonese Opera Appreciation Class, Feng Shui Class, Maritime Museum, Guided Tour, Chinese Tea Appreciation Class, Antiques Appreciation Class, Jewellery Appreciation Class, Dr Sun Yat-sen Museum Guided Tour, "The Hong Kong Story" Exhibition Guided Tour, Kung Fu Corner, Chinese Medicine Class and the Chinese Cake-Making Class.
These offers can be found at the Discover Hongkong site at http://www.discoverhongkong.com/eng/heritage/ck/index.jhtml. It is for visitors only who are aged 3 to 70. You'll have to show your passport when attending one of these. I think I'll check out the Hong Kong Story Guided Tour so Ikee can benefit from it.