You can login to the Yun without the hassle of entering the password you set for it, this is supposedly even more secure than the normal way.
All the details are at http://wiki.openwrt.org/doku.php?id=oldwiki:dropbearpublickeyauthenticationhowto but here is the short version for Linux, Windows looks more complicated but the link above covers the details.
First check if you already have a public DSA key:
If you get “No such file or directory” then do this:
ssh-keygen -t dsa press enter three times at the prompts.
Now do this:
scp ~/.ssh/id_dsa.pub root@<yourYunsname>.local:/tmp
ssh into the Yun (using your password for the last time!) and:
cd /etc/dropbear cat /tmp/id_*.pub >> authorized_keys chmod 0600 authorized_keys
exit the ssh session and restart it, NO password prompt!
If someone knows how to implement this on the web interface it would be great.