The first thing I installed when I updated to 6.1 was DebianSaverLaunchDaemon (which I installed from a previously-saved .deb file I had created using the same.)
Then I installed all my other tweaks (long list
here), and the debs all got saved to the /private/var/movile/Documents/DebianSaver directory.
Just before I updated to 6.1.1, I copied the whole folder of saved .deb files to my computer. I also opened MobileTerminal and ran “dpkg -l > applist.txt”, then saved that to my computer as well.
I backed up in iTunes, restored to 6.1.1, restored from backup, and backed up again.
Then I ran evasi0n 1.3 and jailbroke. I opened Cydia once, let it set up its directories, and closed it.
The first thing I installed in 6.1.1 was DebianSaverLaunchDaemon.
Then I copied all the .deb files corresponding to tweaks in the applist.txt file (meaning they had been on my phone immediately before I updated to 6.1.1) from my computer to my phone at /private/var/root/Media/Cydia/AutoInstall and restarted the phone.
Everything got installed, without my having to connect to the Cydia servers or download anything.
My Activator setup seems to have disappeared, but all my other prefs are intact, so I just went through and set up Activator how I want it.
If and when I ever upgrade my jailbreak to a future iOS version, the first thing I install will again be DebianSaverLaunchDaemon, and I will always keep a backup of my installed .deb files so I can easily reinstall them.