>Personally, my work qualifies depending on your definition of n-tier. I use business objects and data brokers but they generally are within a VCX internal to the app so it's virtual n-tier but physically 2-tier.

Sure John! Remember, n-tier design is two sided: logical and physical. Yours might be only logical but it would be just little more work to convert it into physical if/when you want or need to.

Just curious before I setforth on my n-tier journey, how much more work, in your opinion, was/is needed in your projects? I know there's more coding involved since word "bound" (e.g. controls) becomes somewhat meaningless. In addition, have you tried physically separating the UI from BO (separate EXE/DLL), and if so, what is your experience?