AptOnCD is a nifty utility to back up your downloaded packages in Debian-based distros such as Ubuntu and Linux Mint. If you want to muck around the file system, just open this folder as root (or Administrator in Linux Mint):
and copy all the deb files to a separate hard disk.
This is a crude mechanism for backup but it will save you the trouble of restoring a deb package should the need arises.
Case in point: Minitube
With version 1.3 of Minitube, you can make multiple downloads of YouTube video but not with version 1.4 (the latest as of this writing). So, just remove the current version from the Package Manager and double click your old deb package, and voila, it’s done. It’s that easy.
Just don’t forget to back up your deb packages regularly. Version control ensures that you won’t miss the functionality you want that otherwise might be removed in future versions.
Download Minitube 1.3 deb package here for Ubuntu Lucid and Linux Mint 9.