It just weighs only 650KB for download and does not require an installation. This free reader has almost all functions of a PDF reader, but missing a few options like search function.
Another feature is that you can also convert the PDF document into TXT, BMP, JPG, GIF, PNG, WMF, EMF, and EPS.
However while testing here, the reader shows some shortcomings. It takes little long time to load the page and scrolling page is also little laborious. But the converting speed not so bad. If you like, download Cool PDF Reader from the home page.