Another nice way to create users on linux that have just rights for scp/ftp/cvs/rdist/rsync is RSSH (restricted ssh).

Example (for debian)


apt-get install rssh

configure the rights by editing the config file (uncomment the things he should be able to do)

vi /etc/rssh.conf

add user or modify a already existing user

useradd -m -d /home/heinzi -s /usr/bin/rssh heinzi
usermod -s /usr/bin/rssh heinzi

Now the user can just access by the application you choose for him in rssh.conf.