Entity Framework - Don't Forget to Detach

Often in the web programming model, we make use of disconnected data sets. When using LINQ-to-Entity to fetch data, you have to remember to call the Detach method of the context. If you do not detach the object, the context continues to maintain a reference which keeps it from being garbage collected.

Here's an example:
public Customer GetById(int aId) {
DataEntities de = new DataEntities();
var retVal = (from iterCust in de.Customers
where iterCust.Id = aId
select iterCust).FirstOrDefault();
de.Detach(retVal); //detach the object from the context
return retVal;
}

You do not have to do this when you set the NoTracking MergeOption (set de.Customer.MergeOption).