I've been searching around and I found this post:
http://guitar-fx-layouts.42897.x6.nabble.com/Stereo-to-Mono-Sum-box-td19944.htmlBut I'm not sure I understand the link to rane.com fully. I have a pedal board that splits to stereo at my delay and stays stereo through my reverb. I play at a number of locations... some of them offer stereo access and some don't. A switch or pedal that would allow me to leave my board wired stereo and just plug in mono at those locations would be awesome. Passive or active is fine. I don't need an LED or anything.. the simpler the better.
Thanks for your input and advice.