I had mentioned to the North Dallas DNUG when I presented a while back that I didn't like the idea of passing back a DataReader at all from a DAL.  You lose control of what happens to it when you do (as in the DAL no longer has the responsibility of closing the reader and ensuring its disposal).  Well, Teemu Kieski had a great idea ...

Aaron blogged about interfaces and asked about people usage.  I have been using them more and more in code.  Here are some examples of closing and disposing of System.Data (and Microsoft.Data) resources using interfaces: static void DisposeIDbDataAdapter(ref IDbDataAdapter da) { if(da != null) { if(da is IDisposable) ...