LOL
So you've rediscovered the "con"...
Anybody remember the interlnk and intersvr utility bundled with MS-**** 6.xx?
Not DOS, but OS/2 related : to "clone" an entire hard disk (and, yes, it will boot) you will use xcopy c: d: /h/o/t/s/e/r/v
Other DOS tricks :
Prompt $p$g will give you the familiar C:\> prompt. I have had lots of fun in changing the prompt to C:\PORN> and see people frantically trying to CD\ back to the root, or trying to view the non-existent pr0n files...
To do so, type in (at the command prompt) Prompt $pPORN$g....
Also, should you have ansi.sys loaded, you can have colored prompts... I think it was prompt $p$e3,33$g something, it was yonkers ago...
In Win2k and XP you can change the console window size by typing in MODE CON: COLS=80 LINES=25 (or whatever). In OS/2 this was an great way to get a "scroll" buffer...
There's other DOS tricks and stuff which I can hardly remember now...