I have had problems with xpdf though, I can open the files from a tmp folder immediately after downloading, but when I try to save them to my drive, they won't open again from the saved location.
System requirements for Acrobat Reader 5 are
Linux 2.2 kernel on X86 computer
64MB of available RAM
26MB of available hard-disk space
it comes in a tar.gz form.
you can download it from www.adobe.com
If you use KDE, you can use this next tip too.
If you still have GhostView opening your pdf files for you, browse through your files in a navigator window, and left-click on any pdf file icon. Choose "open with", then type in the name you saved Acrobat reader under, or browse for the file. Choose "remember application association for files of this type". Then open the file.