I use Foxit Reader to view PDF’s simply because of the many vulnerabilities in Adobe Reader.

Adobe has now announced, that Adobe Reader will be available in “protected mode” in the next major release (Protected mode has also been used in applications like Internet Explorer, Google Chrome and Microsoft Office 2010). In “protected mode” Adobe Reader will display the PDF file on the PC in a “very restricted manner” inside a sandbox.

Read more on The Adobe Reader and Acrobat Security Initiative here
Read more on Adobe Reader Protected here