Being in a wheelchair doesn't slow down Carl Brinker as he rappels the overhang wall on the Cliff Lodge at Snowbird Friday. Snowbird has been the site this week of a conference of the National Association of Developmental Disabilities Councils. In addition to meetings and workshops, participants enjoyed the rappeling exhibition and scuba diving by people with a variety of developmental disabilities. Rappelers included Brinker, a paraplegic; Tom Whittaker, who lost his right foot and had his left leg crushed in a car accident; Kyle Packer, who has cerebral palsy; and Steve DeRoche, who had below-knee amputations at age 5.