CXPACKET just means you have parallelism.  It doesn't on its own mean you have a problem with parallelism.  Please don't blindly reduce parallelism just for the sake of it.  How many processors do you have and what are your max degree of parallelism and cost threshold for parallelism?  Are you seeing any memory pressure?  Do you have anything going on that involves lots of data churn - batch processes or index maintenance, for example?

I recommend you have a look at Paul Randal's posts on wait types if you're new to this stuff.

John