tar

[William T Wilson <fluffy@dunadan.com>]

Here is the proper syntax for tar:

(cd <olddir>; tar -c <filespec>) | tar -C <newdir> x

It will copy files in <olddir> into <newdir>.  Use 

(cd <olddir>; tar -c <filespec>) | tar -C <newdir> xp

to preserve permissions.
It is Better than using a temp file.  :)