Probably everyone in Southwest Minneapolis is already aware of Mr. Little Guy's house but if you have not been to his house you ought to go.
I, unfortunately, cannot claim credit for this 'cache' although I have known about it for many years.
Mr. Little Guy's house is like a standard cache in the sense that you can leave something and can get something but in this case what you leave are requests for advice and what you get are personal responses a week or two later. Be prepared to leave a note for Mr. Little Guy as he isn't often at home.
Mr. Little Guy has plenty of visitors so you shouldn't have too much trouble finding his house.
Note that Mr. Little Guy goes South for the Winter so be sure to stop by during the non-snowy one or two months of the year.