dir | clip – copies the output of the dir command to the clipboard
clip < example.txt – copy the contents of the file example.txt to the clipboard

C:\sdk\windows\v6.0a\include\ws2def.h(91) : warning C4005: 'AF_IPX' : macro redefinition
C:\sdk\windows\v6.0a\include\winsock.h(460) : see previous definition of 'AF_IPX'
C:\sdk\windows\v6.0a\include\ws2def.h(124) : warning C4005: 'AF_MAX' : macro redefinition
C:\sdk\windows\v6.0a\include\winsock.h(479) : see previous definition of 'AF_MAX'
C:\sdk\windows\v6.0a\include\ws2def.h(163) : warning C4005: 'SO_DONTLINGER' : macro redefinition
C:\sdk\windows\v6.0a\include\winsock.h(402) : see previous definition of 'SO_DONTLINGER'
C:\sdk\windows\v6.0a\include\ws2def.h(206) : error C2011: 'sockaddr' : 'struct' type redefinition
C:\sdk\windows\v6.0a\include\winsock.h(485) : see declaration of 'sockaddr'
C:\sdk\windows\v6.0a\include\ws2def.h(384) : error C2143: syntax error : missing '}' before 'constant'
C:\sdk\windows\v6.0a\include\ws2def.h(384) : error C2143: syntax error : missing ';' before 'constant'
C:\sdk\windows\v6.0a\include\ws2def.h(384) : error C2059: syntax error : 'constant'
C:\sdk\windows\v6.0a\include\ws2def.h(437) : error C2143: syntax error : missing ';' before '}
(...)

After some digging in the code I noticed that windows.h had been included before winsock2.h. And that windows.h includes winsock.h. When digging deeper, I found an article in the MSDN describing what had happened here:
actually, this is a legacy problem. In Windows versions <= Windows 98, WinSock 1.1 had been used. The current win32 socket implementation, Windows Sockets 2 (WinSock 2.0), is backwards compatible to Windows Sockets 1.1. Additionally, the winsock2.h header files prevents the inclusion of the legacy winsock.h header file. But once you include winsock.h, you can not include winsock2.h later on.
Unfortunately, windows.h still includes winsock.h.
Fortunately, you can disable the legacy parts of the Windows SDK easily:

#define WIN32_LEAN_AND_MEAN

You will not be able to build Windows 95/Windows 98 applications when using this definition. But if you were targeting those OS versions, you wouldn’t be using Windows Sockets 2 anyway.

• tasklist: shows a list of all running processes
• taskkill: kills processes

Among other options, processes can be killed by their process ID (taskkill /PID 4711) and by the name of their executable (taskkill /IM firefox.exe).
So, if you have perl scripts running wild, just execute taskkill perl.exe to kill all of them down with a single command.

More lesser known Windows commands are described in this PDF.

Update:
zdnet provides (less verbose) background information on how the iPhone got hacked at the same event.

1. Create a wrapper script (e.g. git-diff-wrapper.sh) and put it anywhere in your Windows path (%PATH%):
   #!/bin/sh
"C:/Program Files/WinMerge/WinMergeU.exe" -e -ub "$1" "$2" | cat
2. Update your .gitconfig to run this script whenever “git difftool” is invoked:
   # … more config …
[diff]
tool = winmerge
[difftool "winmerge"]
cmd = git-diff-wrapper.sh "$LOCAL" "$REMOTE"
# … more config …

That’s it, no restart required

• are free/open source,
• create checksums for multiple files,
• export checksums to a file,
• and verify md5 sums from a list of files.

In short: if you need a very good tool, then use the Swiss File Knife (sfk).

For creating checksums for all your files in the current directory and storing the individual checksums in checksum.md5, execute this:

sfk md5gento checksum.md5 .

And for validating the checksums of all files in the current directory, execute this:

sfk md5check checksum.md5

That’s it

Ok, nearly all the plugins you will need

Have a look at pymssql.sf.net for a  Microsoft SQL Server module.