As an ASIC design house we have do work closely with our customers to when designing the IC's application PCB. We frequently get Gerber files for layout review since we do not have all of their layout tools.
We frequently have to trace a net's connectivity to make sure that things are going to work in real life. Gerbv is great for reviewing but it would be even better if one could select and highlight physically connected areas on each layer.
I'd be extremely happy if this feature could be implemented. Thanks for writing such useful software.