PDF and Power Point Presentations can be displayed in any self hosted WordPress plugin which can be downloaded from:
http://downloads.wordpress.org/plugin/pdf-and-ppt-viewer.0.0.1.zip
you can have all other details related to plugin on this page
http://vladimir-k.blogspot.com/2009/09/pdf-and-ppt-viewer-wordpress-plugin-for.html
PDF and PPT Viewer supports all modern browsers. The plugin doesn’t require installation of non-standard PHP extensions on your server, so you will not have problems with your hosting provider. PDF and PPT Viewer works with WordPress 2.8 and higher.
A live example is shown below
