Providing an ad-hoc report facility for business users in SQL Server 2008 R2
You're probably looking for Report Builder 3.0 and/or Power Pivot.


  Microsoft SQL Server 2008 R2 Report Builder 3.0 provides an intuitive
  report authoring environment for business and power users. It supports
  the full capabilities of SQL Server 2008 R2 Reporting Services.


Your Excel ninja users will likely prefer Power Pivot, your more typical tabular report folk will feel right at home with Report Builder. There's a useful summary of the differences between Report Builder and the BIDS Report Designer at Designing Reports in Report Designer and Report Builder 3.0 (SSRS).