How to start a user process on boot?

[Carsten Schulz <Carsten.Schulz@urz.uni-heidelberg.de>]

Hi,

I want to start a p2p program while booting. I tried to write a script 
for /etc/init.d it works but only as root.
I want the program starting as a user process (for security reasons).

How can root start automatically a process as a user?


Thanks,
	Carsten