Linq to SQL is a very nice abstraction when dealing with MSSQL, specifically the ability to conduct Linq queries in C# against MSSQL is pretty sweet. Updating a row through an ORM object, e.g. a HTTP Put, into the DB without doing manual field copying between the tracked entity and the de-serialized entity from the PUT is however a bit troublesome.
.Attach allows one to attach an entity to a Context, however calling SubmitChanges will not submit the changes of the attached object due to it not being marked as modified. Calling Attach(entity, asModified) with asModified = true did not work for me - an exception was thrown.
Apparently, this overload can only be called with asModified = true IFF Update Check is set to Never in the DBML file. This needs to be done for all properties of the given entity class, not sweet, but at-least it avoids the need to manually copy each member to an existing tracked Entity in the Context.