Further to my last post regarding Linq to SQL. I have been searching the net, looking for examples of how one might use Linq in an n-Tier world.
Short answer is there isn't really any. The vast majority of examples you will find are for a 2-tier model, where the DataContext is alive across the call, and the Entities will always be attached to the DataContext. Unless you are developing utilities, or you code will always be executed in the same box as the database, then this isn't really real world examples.
With a bit of digging, I have found a series of articles on the MSDN site here with the most useful being this one.
The readers digest version for those of you who are too lazy to read the articles, is that you need to serialize your Entities and then use the Attach API to "reattach" them to a DataContext.
There are some gotcha's, most important of all being you may have to handle concurrency issues yourself.
I intend on posting some code once I have digested the articles and found time to do some playing, but I would suggest you do some digging of your own, and those articles would be a good place to start.