Thank you for your answer, I was reading it, and I started to think in the use I give to the machine. Your idea, exactly as you posted it, isn't suitable in my case, but with a little modification, I could apply it in a different way.
Before anything, I dont know if my personal case should deserve a new thread. If is, tell me and I'll repost it for avoiding spamming this one.
In this exact moment, this is my (disordered) partition system.
The first unallocated 7.8 MB were left there by Windows setup. I dont know why, but it I put the boot zone at the exact beginning, Windows doesn't boot up. (with Linux the problem doesn't exists- I noticed that when I tried Debian).
The NTFS partition (mounted on /media/disk-1) is the Windows partition. I have 8 GB on there, but for what I have installed on it (MicroXP, Macromedia Flash 8, AIMP, K-Meleon + essential drivers), I think is much.
The following is my / partition, in which there's all the Linux filesystem (/home included). You see 12.27 GB used, but in reality, is less than that, because I have 4 GB from a couple of torrents I've downloaded (and there's still 700 MB of downloading to complete), and lots of downloads on /home/victor/Downloads. I'll do all the formatting and such when torrents are done.
Swap, no need to description.
That fat32 partition (I dont know why it's labeled as boot, btw, I noticed it now that I wanted to check my current partition configuration), has all the data I could consider important. Has my music, videos, programming codes, a mirror of my website (I update it weekly), games and such. Is fat32 because I needed access to it from Windows too.
Now, you can see that the partitions are almost full. When I format I plan to have my music, some information, and a small 3~4 GB virtual machine with MicroXP. The problem goes to the fact that soon I start to fill the machine with files, downloading huge packages, or when I go to a friends's house, as example, when we modify things, videos for the university, things like that. Short tale, I use the machine and in a lot of situations my hard disks are occupied at 90% or more. That's why a backup into the computer could be unsuitable or space occupying.
(Fun fact: When I received this laptop the very first thing I did was deleting the backup partition for using it with my data).
But there's a possibility. Not in this moment, soon (im poor) I plan to buy one of those cheap 4GB USB drive. The same idea of a backup could be applied to there; making the copy to the USB drive. That could help me with the reinstallation in the future, and to have that couple of GB extra (that in a moment becomes super important).
In general, my laptop is super multiuse, depending of my mood and patience, and I can say I've used it for anything, since listening to music, to playing OpenArena (when I had Windows- on Linux, it doesn't run). The max use I give to it -apart to the normal websurfing/music/messaging- is drawing. That's why I have Gimp, Inkscape, MyPaint (I could make a tutorial for installing it), GNU Paint, etc. Installing software isn't the thing that worries me- indeed, sometimes due to that I like to start again-, the thing that worries me are the drivers.
Thank you for the suggestion, and even if I'll dont apply it exactly as you told me -apart to the fact that possibly I'll update to Mint 8 when it's released-, I'll definitely use the idea. Thank you for your time too, is widely appreciated.
PS: Sorry for my bad english; I speak spanish.