Generally, you will have to install the corresponding package (which contains the missing library), too.

Examples:   

•  Fedora7:     error while loading shared libraries: libXp.so.6: cannot open shared object file: No such file or directory               
  

  yum install libXp # note the upper case "X" and lower case "p"    

• RHEL5/64bit:
      /opt/t32/bin/pc_linux/t32mppc: error while loading shared libraries: libXmu.so.6: wrong ELF class: ELFCLASS64
      Not all necessary 32-bit packages are installed.
      The 32-bit "libXmu" package and all its dependencies should be installed.   
•  Ubuntu 12.04/64bit:
      error while loading shared libraries: libjpeg.so.62: cannot open shared object file: No such file or directory

    sudo apt-get install libjpeg62    

• OpenSUSE 13.1/64bit:
      error while loading shared libraries: libjpeg.so.62: cannot open shared object file: No such file or directory
      Install missing package libjpeg62 with YaST
  
      error while loading shared libraries: libXp.so.6: cannot open shared object file: No such file or directory
      Install missing package libXp6 with YaST