Per user tmp?

[Bruno Wolff III]

On Mon, Sep 01, 2008 at 15:37:18 +0300,
  Gilboa Davara <gilboad at gmail.com> wrote:
> Hello all,
> 
> Any idea how I can setup a per-user tmp directory?
> E.g.
> USER1 has /tmp -> /tmp/USER1, /var/tmp -> /var/tmp/USER1.
> USER2 has /tmp -> /tmp/USER2, /var/tmp -> /var/tmp/USER2.
> etc.
> 
> In short, I want each user to have a private /tmp, and /var/tmp -
> without having to resort to using virtualized/jailed environment.

Another approach is polyinstantiation. See:
http://www.ibm.com/developerworks/linux/library/l-polyinstantiation/?ca=dgr-lnxw02LinuxPAMSecurity&S_TACT=105AGX59&S_CMP