At our school, we also organize parent volunteers into providing dinner for the teachers and anyone else at school for conferences. It's the little things like that to make it easier, the least we can do!
while creative ideas (carwashes, thank you posters) are refreshingly different, parent/teacher conferences are almost always VERY long days. our PTO always provides dinner for teachers and aides that day (homemade by parent volunteers). it usually consists of two soups, a hot entree, sandwiches, 3 sides/salads, bread, 3 desserts and beverages. you would not believe how much the teachers look forward to that respite before digging in their heels for the long evening ahead and they ALWAYS look forward to it! bottom line? never underestimate the appreciation of a meal!