Delve automatically searches the internet for computers that share any drives via Apple File Sharing (AFP) or Windows File Sharing (SMB).
This simple application is a showcase of the unsecure terms under which people handle their private data. As you will notice you can sometimes access someone's entire harddrive directly over the internet. This is most often not intended.
The latest version is 1.0b3, download it here.
Note that you'll need Mac OS X 10.5+ to run Delve.
Source code is available at GitHub.
Now you need to login with your system username and password to get access to the shared folder, instead of it being open to anyone. Repeat the above steps for all folders you are sharing.
Delve is licensed under GPLv3.
This software uses nmap, for more information see the COPYING file. Source code for nmap is available at http://nmap.org/