This is a small post but i think some people have help on this one.
Because i am sharepoint programmer i am almost doing everything web based.
But it is a lot of work if you make a change to your wcf you don't want to change your SharePoint for fast debugging
Well the solution is very easy just create a windows application and reference it to your wcf dubug service.
You have to have your wcf service running in debug mode so you can fast change things.
it will save you a lot of time in the end especcially if you don't know what the output of your wcf will be