Husband and I collect cookbooks from restaurants we visit, mostly New Orleans and we have the staff involved in our experience sign them. Best was Susan Spicer's from Bayona if you are looking for recipes. Most interesting was from I believe, but am probably mistaken, the Colonial Inn in Philadelphia with recipes and history from the colonial days. George Washinton ate at this site in the original building. Current restaurant was rebuilt to the specs as the original burnt to the ground.
If there is no cookbook we ask for a menu or even a napkin signed by the staff. Have a wonderful menu from a restaurant located in Graz, Austria.
When we have explained we cook, collect and enjoy dining out we have received the most memorable items and stories. People love that you love their work.
All this stuff is at home in the US and I am in China, this thread reminded me to get back on track and continue a wonderful hobby. Also we need to learn to cook here as were have no oven or outdoor grille.