>>>
>>>We use the 5 - layer approach (actually ours has a couple more layers) and MVP pattern for our desktop and web apps.
>>>
>>>Luis, if you are interested, there are some good podcasts with examples on the MVP pattern here:
>>>
>>>http://polymorphicpodcast.com/shows/mv-patterns/
>>>
>>>As someone pointed out in another thread, there are more design patterns to choose from including the MVC, MVP, and now the MVPC pattern :) Lots more to read up on. Lots of information on the web about it all.
>>
>>Not only are there sample applications out there there are a number of good n-Tier frameworks. IdeaBlade (www.ideablade.com) has a product called DevForce that is one of the best n-Tier frameworks I have seen. It works with VB.Net and C#. They have an express version that is unlimited free use for applications with up to 10 tables. DevForce allows you to write UI neutral business objects and tie them to UIs using WinForms, ASP.Net, Silverlight, or WPF. Currently I am using it to write a desktop app and we intend to use the same business logic in a web app later.
>>
>>They have very good documentation. Even if you don't use their framework you can learn a lot from the documentation.
>
>Does it allow for a service layer and WCF?

What exactly do you mean by a service layer? I think I have heard that term used to mean multiple things.

I seem to remember seeing reference to WCF in the documentation. Currently I am doing n-tier architecture with it, but single tier deployment. No advanced communications has entered the picture for me yet. I am using DevForce to extend an older VFP system witch is all single tier. At some point I will be taking the new .NET parts to full n-tier deployment, just not now.