'su' without password

[Pol]

Smoot Carl-Mitchell wrote:
> On Wed, 2009-02-18 at 12:58 +0100, Pol wrote:
>> How to let user1 'su' user2, without entering password?
> Then user1 can run a command as user2 by typing:
> 
> sudo -u user2 command args ...

It seems that 'command' does not get the environment of the user2, this way.

I would  start application of user2 (konqueor web browser) into the .kde of
user2. (konqueror complains that dcopserver of user2 has not started),
rather than .kde of user1.

Thank you
--P