Several people have mentioned their favorite templating tools, but I thought I'd throw out something perhaps more useful -- specifically, how to choose a templating system. I shan't muddy the waters by mentioning my favorite, of course. *grin*

perl -pe '"I lo*`+$^X$\"$]!$/"=~m%(.*)%s;$_=$1;y^`+*^e v^#$&V"+@( NO CARRIER'