ocz is fairly good ram, but that seems a bit pricey for ram of those cas timings and of that size. you could easily have gotten some corsair value select 512mb dual channel (way better than single channel).
1 1 , Dual channel ram is just 2 normal sticks of ram, they called it dual channel ram also called Dual channel ram kit for maketing. since dual channel ram is nothing more then 2 sticks of ram that been tested to work together.
Just buy another stick of those to run it in dual channel if ur motherboard supports it. Read ur motherboard manual to see how to set it up to run in dual channel mode IF your motherboard supports it.