Monitoring globular star clusters
I bet a lot of planets that form in globular star clusters get knocked
around and kicked out of their orbits. A few of these wanderers might
pass in front of a star as seen from Earth, and with hundreds of
thousands of stars in a typical cluster, this increases the odds.
I know there have been a few such searches already, but there have
only been a few and they need to do more with improved techniques.
Unless of course there is something about such clusters that makes
it difficult for planets to form in the first place.
http://hubblesite.org/newscenter/archive/releases/2000/2000/33/text/
There is this other idea about globular clusters:
http://www.aeiveos.com:8080/%7Ebradbury/MatrioshkaBrains/GCaA.html