The web service EmbedIt.in from Increo allows you to embed files or URLs into any existing web page. The service is simple, free and entirely web-hosted.

Embedit.in supports most common file types:
* Documents: doc, docx, xls, xlsx, ppt, pptx, pdf, wpd, odt, ods, odp
* Images: png, jpg, gif, tiff, psd, bmp, eps, ai
* Text: txt, rtf, csv

To use the service, upload your document to their site. After the document is processed, you are provided with the associated embed code. For the example shown below, the code looks like this:

<embed allowFullScreen="true" height="400" width="466"
src="http://embedit.in/5pas3RVJdA.swf" 
type="application/x-shockwave-flash"></embed>

EmbedIt.in generates a customizable Flash-based viewer that includes zoom, download and full-screen options as shown below using a PDF file.