Biophysicists have long been interested in the phase behavior of lipids and the specialized roles that cholesterol plays in membranes. These questions have enjoyed renewed interest in light of the development of the lipid raft model. However, the relationship between so-called liquid-ordered domains in vitro and in vivo remains uncertain. Despite the ease of generating cholesterol-enriched microdomains in simple lipid mixtures, lipid rafts have proven remarkably difficult to identify in intact cells. The call for papers for the recent Biophysical Society Discussion meeting on ‘Probing Membrane Microdomains’ described the raft field as having reached a technical impasse. How can we best study these elusive domains? In this meeting report, I summarize the efforts of the biophysical community to increase our knowledge of raft structure and dynamics. Streaming video of the meeting is available on the Biophysical Society website at http:// www.biophysics.org.