Watermark in reporting services 2008

Reporting Services doesn't have a specific way to produce watermarks, but you can create them manually.
Look at the capacities of the printer driver you use to create a paper copy of the report. Many printers, even low-end ones, have the ability to add watermarks as part of the print process. You may simply create a bitmap with the appropriate watermark on it and set that as a background image for the header, body or footer of the report. Another approach would be to create a textbox behind the report grid and place the needed watermarking there. In both cases, you would probably need to set the background for all cells on the grid to "Transparent" so that the background items would show through; any colored items (even if they use white) would overprint the image.