install acroread in fedora

wget http://ardownload.adobe.com/pub/adobe/reader/unix/8.x/8.1.2/enu/AdobeReader_enu-8.1.2-1.i486.rpm
yum -y localinstall --nogpgcheck AdobeReader_enu-8.1.2-1.i486.rpm
/bin/rm AdobeReader_enu-8.1.2-1.i486.rpm

Debian commands

To have alternate versions of the same program like matlab, java, etc
man 8 update-alternatives
/usr/sbin/update-alternatives --list matlab


To install a new font (true type) put the font in /usr/share/fonts/truetype/ (in debian) and run
fc-cache -fv
then restart X ( /etc/init.d/gdm restart if using GNOME display manager)


To sort folders in current directory by size
du --max-depth=1 ./ | sort -n -r