I wrote an article about LINQ to SAP at CodeProject.com, a new LINQ provider I developed for the company Theobald Software GmbH in Stuttgart, Germany. This provider allows you to easily connect to SAP/R3 systems using the LINQ technology and a Visual Studio 2008 Designer. LINQ to SAP is part of the ERPConnect software suite that interconnects SAP/R3 systems with .NET. You can find more details here.
