HAARP will be conducting an HF moon bounce experiment on January 19th
and 20th. Here is a partial excerpt from the ARRL bulletin:

Interested radio amateurs are invited to participate in this
experiment by listening for the lunar echoes and submitting reports.

On January 19, listen on 6.7925 MHz from 0500-0600z, and on 7.4075
MHz from 0600-0700z. On January 20, listen on 6.7925 MHz from
0630-0730z and on 7.4075 MHz from 0730-0830z (depending on frequency
occupancy at the time of operation, it may be necessary to adjust
the frequency slightly).

Based on previous experiments, investigators believe it should be
possible to hear the lunar echoes with a standard communications
receiver and a simple 40 meter dipole antenna.

Just goes to show you what can be done with a bazillion watts... ;-)

Complete details can be found at http://www.arrl.org/?artid=7958