Notices

dpkg-repack
but be carefull with (post|pre)-install scripts ... the generated package is not exactly the same as the original one.
I think you can get dpkg-repack from debian repository (it's a perl script)

Why not jsut use BackupMenu, then? it's made for the purpose and it's easy to use. But i think there is a way to repackage everything using dpkg-deb...

what about a simple :

this copies the debs to the given folder. of course, you have to run the command every now and then, lest some debs get flushed. it seems that this will suffice for non-programers like me, who just need to be able to re-install packages without re-downloading. (of course, all the general risks of doing things as root apply)

However, this doesn't explicitly group applications with their dependencies, but they are still there, and can be installed via

as mentioned before by others. I actually use the above method on my Debian PC which rarely gets access to Internet connection.

and, great link Drexxx

Initially I used dpkg-repack but that won't include manpages for instance for all the installed debs. I also made a simple script to do all that as well but I found out red pill mode gives an option for one to disable cleaning apt cache which would leave all the downloaded debs in /home/user/MyDocs/.apt-archive-cache/ as per wiki states.

Though using this would only be effective for HAM (Hildon Application Manager), which meant that if say for example you used apt-get or FAM (Faster Application Manager) those deb files for instance would be saved in /var/cache/apt/archives.

Needless to say is that you can optify /var/cache/apt but for making /home/user/MyDocs/.apt-archive-cache the only place for downloaded debs to go you will need to add a line into your /etc/apt/apt.conf.d/00maemo:
This of course will not work in cases like using aptitude download where it will just download the deb file into your pwd (present working directory).

As for installing debs and its dependencies automatically, dpkg does not natively do that. For getting it to work you'll need to create a small apt repository (and ideally not on your device as reflashing will make you lose your setup).

thanks to all of you, helped me alot

I don't mind if someone came up with a more affective way

backupmenu works great but why not copy the deb files to your pc and after the flash, reinstall and maybe do an apt-get update and apt-get upgrade for missing or unmet dependencies.

Where are the debs situated when you download them from the store...? Specifically for harmattan though... I'm not a fan of the backup/restore process, I'd rather keep myself a folder of my deb files and choose what and when to install.

I'd guess Harmattan does not keep a cache for store packages simply because that would enable people easily to redistribute paid / non-free stuff.