Customize the Titles of iTerm Windows or Tabs

Add the following line in your .bash_profile:

export PROMPT_COMMAND='echo -ne "\033]0;${USER}@${HOSTNAME%%.*}: ${PWD/#$HOME/~}\007"'

You could also remove the stupid "Default" by modifying net.sourceforge.iTerm.plist. Simply set Root/Bookmarks/Entries/0/Data/Name as empty.