Think about the kind of socialization experiences you want for your child. Your homeschooled child need not be limited to the artificial community of his or her peers that's offered in the formal school environment, but rather, can benefit from a wide variety of interactions and relationships.
Contact your public school about having your child participate in whatever extracurricular activities it offers. Many districts welcome the participation of homeschooled children in sports teams, clubs, theater productions and other activities. (You may have to sign a waiver releasing the school from responsibility for your child.)
Consider the same kinds of resources you would if your child were in a traditional school environment. Many township organizations, nonprofit groups, and clubs such as bands and orchestras, scout troops and 4-H have chapters devoted to homeschooled kids. If not, your child can still participate "after school," like everyone else.
Join a local homeschool group. Most offer a broad range of activities, including field trips, where your child can benefit from group interaction.
Take advantage of the flexibility homeschooling offers. Socialization could mean bringing your child with you to one of your own church or community group activities, or having lunch with Grandma.