The excellent National Trust store (http://www.nationaltrust....) in Rhossili has a good selection of handicrafts and gifts, many with local flavor.
Local Produce
Gower wildflower and local produce centre (http://www.gowerwildflowe...), blackhills lane, fairwood common, opposite swansea airport. sells an assortment of produce from local farms such as gower wild flowers and gower salt-marsh lamb.