Recently while working on a SmartClient application, I ran across the need to do some data manipulation to create a new column on a DataTable that was a concatentation of other columns in the table. In this case I needed a full address column that was made up out of address1, address2, city, state, etc. columns. While this can be done using SQL on the client side, data access tier or database tier (stored proceedure SQL), it can also be done on the client or application tier using !DataSet/!DataTable manipulation using column expression. You can find basic information about how to do this in the MSDN documenation, but what you won't find there (or at least I didn't) is some of the column expressions that you can create from either parent or child DataTables. There is a good article on how to do this in this MSDN Data Points Column article.