  From 22 to 26 June 2020, we hosted ESO's first live e-conference, #H02020,
from within ESO headquarters in Garching, Germany. Every day, between 200 and
320 researchers around the globe tuned in to discuss the nature and
implications of the discord between precise determinations of the Universe's
expansion rate, H0. Originally planned as an in-person meeting, we moved to the
virtual domain to maintain strong scientific discourse despite the SARS-CoV-2
(COVID-19) pandemic. Here, we describe our conference setup, participants
feedback gathered before and after the meeting, and lessons learned from this
unexpected exercise. As e-conferencing will become increasingly common in the
future, we provide our perspective on how e-conferences can make scientific
exchange more effective and inclusive, in addition to climate friendly.
