I live in a terrace of houses and ten doors down is a really nice pub that does great food. Would it be horribly irresponsible to leave the kids (8,4 and 2) home alone with a video (+audio) monitor watching the doors to the bedrooms, toilet and hallway? One of us could be home within one minute of seeing / hearing a child but in the mean time we could be sat having a couple of pints and a tasty meal with friends with a laptop/ipad on the table showing what's going on in the house.
I suspect this isn't ok and haven't suggested it to my wife yet but wanted to canvas opinions. You could get the kit to do this for ~ £100 which is what 4 baby sits would cost.