I'm flying from Quebec to San Francisco on Friday, San Francisco to Tokyo on Monday, Tokyo to San Francisco in January, and San Francisco to Quebec in January.
Quebec has things like
Spruce Beer,
Tim Hortons Donuts, maple candy, Cuban Cigars, and drunk Inuits. San Francisco has things like sourdough bread, tacos, and high quality sex toys. Tokyo has things like robots, obscure video games, cell phones with integrated frying pans, Hello Kitty, and anal eel omolette porn.
If anyone in city X would like me to go shopping for them in city ^X and bring them back something, please let me know. I can't promise anything but I'll try.