For Word 2003, select Format > Background > Printed Watermark. In that
dialog you can choose any picture file or any text for your watermark.
(It may not be obvious, but you can type any desired text into the
Text box if the predefined words aren't suitable.)

You should also have a look at
http://home.earthlink.net/~wordfaqs/BorderArt.htm for a method of
creating custom page borders.

For Outlook, see the Help topic titled "Create stationery for
messages".

--
Regards,
Jay Freedman
Microsoft Word MVP         FAQ: http://word.mvps.org

To create a custom watermark, you must first have a custom
picture to import.  If you have already created a picture,
then you are ready to import it to your document.

In Word, go to Format.  Then go to Background, and to the
right, click on Printed Watermark.  In the Watermark box,
click which watermark you want (text or picture).  For
picture, select the picture you want.  Change any options,
and there you have it.  Its' quite simple.