Increasing the size of your home directory on the fly.
For a long time now I have used LVM to manage most of my disk space on my machines. It's simple once you have understood what it is talking about and it is quite flexible.
I have been running out of space in my home directory on my desktop at home. I have a load of random disks in the box and they are all under LVM. I have been putting off sorting this out for a while now as all the times before that I have wanted to resize drives it's a boot disk job. Not any more.
# lvextend -L +10Gb /dev/maindata_vg/home_lv # resize2fs /dev/maindata_vg/home_lv
That's it. I now have another 10Gb of disks space in my home directory. All online, all in about 30 seconds!
Note: I already had some spare space in the maindata_vg to play with so this was simple but if I had added a new drive I could have just added it to the group and done the same.