Tooltips are a useful thing. Just last year, as a volunteer web developer, I built an event website for a nonprofit. The website had a page with the event program grid. The event had several parallel tracks, each of them jam-packed of back-to-back panels, and each panel had several panelists. Understandably, the web page real estate was at a premium, and the page for the panel grid listed the participants by only their last name. No other info.