If you need a great reporting tool, or you want to use the RDLs from the Reporting Services 2005 without a SQL Server 2005 license, then this link will be very interesting for you (or maybe you already know the ReportViewer? ):

http://www.gotreportviewer.com/

Here's an excerpt from the product description:

ReportViewer is a freely redistributable control that enables embedding reports in applications developed using the .NET Framework. Reports are designed with drag-and-drop simplicity using Report Designer included in Visual Studio 2008 (Standard editon and above.)

The ReportViewer control offers the following benefits:

Processes data efficiently. The reporting engine built into ReportViewer can perform operations such as filtering, sorting, grouping and aggregation.
Supports a variety of ways in which to present data. You can present data as lists, tables, charts and matrices (also known as crosstabs.)
Adds visual appeal. You can specify fonts, colors, border styles, background images etc to make your report visually appealing.
Enables interactivity in reports. You can have collapsible sections, document map, bookmarks, interactive sorting etc in your report.
Supports conditional formatting. You can embed expressions in the report to change display style dynamically based on data values.
Supports printing and print preview.
Supports export to Excel and PDF.

The control can process and render reports independently using a built-in engine ('local mode') or it can display reports that are processed and rendered on a Report Server ('remote mode').

There is a WinForms and a WebForms version of the control.