Fallen Fruit in Chicago?

Last week I visited the Lincoln Park Zoo, but what got me thinking was actually some mulberry trees along Clark. I remember reading an article about a group that makes maps of urban fruit trees for scavenging fruit, so I Googled around a bit and found it- Fallen Fruit in Los Angeles and San Francisco. They encourage people to harvest and use fruit growing on or overhanging public property. I find their website a bit hard to navigate (maybe because I don't know the areas they're talking about) but here's another article about the project.

Chicago should have something like this. I can tell you that I have since discovered a small mulberry tree at 16th and Morgan and another on 18th St. near Cuernavaca. Mulberry trees tend to be unpopular because they drop the berries all over the place and they can stain. Most people don't know that they are great for making pie, cobbler, jam, and more. What fruits and vegetables have you seen growing wild in Chicago?