svn ci -m ‘This works!’ foo.bar

I agree that while I already knew of #6, it took me a moment to understand what the author was saying, but in essence it is that say we have the following scenario, you need to edit xorg.conf.
You type:
“nano /etc/X11/xorg.conf”
and hit enter, but instantly remember that you need root privileges to edit the file, so you quit, now the bad way of doing things is to type it all up again, and adding sudo before it (if you are working on a system which uses sudo ofc), the better way would be to type
“sudo !!”
which is the interpreted as sudo [the last executed command] or
“sudo nano /etc/X11/xorg.conf”

As for #10, try the following:
create a folder somewhere in your system (like the desktop) or whatever.
Create an empty file outside the folder.
(when I tested this I had a “sandbox” folder and the file “foo” on the desktop.)
then I tried
“mv foo sndbox”
which of course failed since I misspelled sandbox.
The next command I ran then was
“^sndbox^sandbox”
Talk about kick-ass stuff

(Of course all of these commands should be without double quotes)

Hope it helped
cheers

@Mark: That’s the “don’t do this” part of number 6.

Also the reason people grep | history is to see the different ways they used a command like, “history | grep mount” will show you what you mounted recently.