you can download the offical adobe acrobat reader version 5.0.9 from
http://www.adobe.com
then just untar it, cd into the new folder and install using
./INSTALL
follow the prompts...
then you have acroread installed and you can create a symbolic link to complete your installation
here is an example ( if you had installed it to /usr/local/Acrobat5 )
ln -s /usr/local/Acrobat5/bin/acroread /usr/bin/acroread
now the command acroread gives you pdf viewing capabilities