How can I uninstall all the packages I've installed today?
Solution 1:
grep -e `date +%Y-%m-%d` /var/log/dpkg.log | awk '/install / {print $4}' | uniq | xargs apt-get -y remove
found on commandlinefu worked fine for me
Solution 2:
The file /var/log/apt/history.log has what you need. Take a look at the answer: How to reinstall many removed packages at once? it's a more detailed answer.