APTonCD is a piece of software that backups all your downloaded software from internet.

1. Download APTonCD using Synaptic and install it. Use this to make a ISO image from downloaded packages.

2. Then you can mount this ISO image and it will just work as the package CD.

3. To mount an ISO image:

$ sudo mount <image> /media/cdrom -t iso9660 -o loop

4. To unmount:

$ umount /media/cdrom

This is the method I am following. Download packages and dependencies using synaptic once. Then copy them from /var/cache/apt/archives/ Then make an APTonCD and share with friends and new installations.