Check out the book Trails of Central Arkansas http://trailsofarkansas.blogspot.com/p/about-books.html for places to hike in Conway, Little Rock, etc. You can meet lots of new people just out on the trail! Two Rivers Park, Pinnacle Mountain State Park, and Burns Park are always busy on nice days.
If you like hiking around the NW part of the state look up a group called Take a Hike on facebook. They're from Springfield, MO and head to northern Arkansas to hike around the upper Buffalo and climb at Horseshoe Canyon pretty frequently.