To highlight a trace, use the command "Query Net" (menu: Info | Query Net...) and select any track. The entire connection will be highlighted.
Great feature! Is there a way to highlight the net as it travels through the board? For example, I have a trace that starts on a component on Layer 8, vias to Layer 3 and vias back to a different component on layer 8. Can I follow the trace from one pad to another easily?