On animal crossing I love to build public work projects. I like to put whatever money I earn to a public work project. Some public work projects can only be requested by villager. However, some of the projects are already on the list at the beginning of the game. As some of you know, you can build a second floor to the museum. You can only do this is you have donated one of everything from each category. One you have built this a week later Blathers will want to speak to you again this time it will be to build the Roost, a cafe also seen in other animal crossing games.
If you want to find out more go to the public work projects on this wiki: