Google Docs Viewer is an online tool that lets you open PDF files online without downloading it. With the gPDF browser plugin, viewing PDF files in Google Docs Viewer becomes easier. Upon installation gPDF rewrites all links to downloadable PDF files on a webpage to open automatically in Google Docs Viewer. This makes accessing PDF files on the web a lot faster, since you don’t have to wait for it to download first.
gPDF is available as a Firefox addon, as Chrome extension, and as a Greasemonkey script for both Firefox and Opera.