Ok, so last post was a bit heavy. How about some more bash. So, thanks to sudo the !! word designator has become very popular:

$ apache2ctl restart
Permission denied: ...

$ sudo !!
sudo apache2ctl restart

Very cool, but you can also reuse arguments with the !! word designator:

$ cp /home/user/some/really/long/path /home/user/foo

$ ls -lha !!:1
ls -lha /home/user/some/really/long/path

So this !!:n lets you grab the nth argument, which is cool.

You can even select ranges:

$ cp /home/user/some/really/long/path /home/user/foo

$ md5sum !!:1-2
md5sum /home/user/some/really/long/path /home/user/foo

You can also use the asterisk to select all the arguments, but not the command:

$ ls /home /

$ ls -l !!:*
ls -l /home /

Anyways, there are quite a few other options so check out the docs: