deb files:

To expand on your desktop do this:

1. Open Terminal and cd to the directory of the deb file
2. Type:

ar vx filename.deb

To install on your iPhone if you choose not to use Cydia do this:

1. SFTP or SCP your deb file into /tmp
2. SSH into your iPhone with Terminal and type:

dpkg -i /tmp/filename.deb