When you type:

cd /? at a CMD prompt, you receive:

"Displays the name of or changes the current directory.                              CHDIR \[/D\] \[drive:\]\[path\]                              CHDIR \[..\]                              CD \[/D\] \[drive:\]\[path\]                              CD \[..\]                                ..   Specifies that you want to change to the parent directory.                              Type CD drive: to display the current directory in the specified drive.                              Type CD without parameters to display the current drive and directory.                              Use the /D switch to change current drive in addition to changing current                              directory for a drive.                              If Command Extensions are enabled CHDIR changes as follows:                              The current directory string is converted to use the same case as                              the on disk names.  So CD C:\TEMP would actually set the current                              directory to C:\Temp if that is the case on disk.                              CHDIR command does not treat spaces as delimiters, so it is possible to                              CD into a subdirectory name that contains a space without surrounding                              the name with quotes.  For example:                                  cd \winnt\profiles\username\programs\start menu                              is the same as:                                  cd "\winnt\profiles\username\programs\start menu"                              which is what you would have to type if extensions were disabled."

The /D switch is new, allowing you to switch Drives and folders in a single command.

A nice undocumented option is the wildcard (*). Type:

cd do*

and it will switch to the "Documents and Settings" folder, the first folder to match the do<anything> pattern.