Good question. None as yet, I am afraid.
Please note that:
1) You received your password with your confirmation of registration (if you provided a valid e-mail address).
2) The password is not stored anywhere in the database (only its hash). Therefore, you can never recover your password, but an admin can change it for you.
Once we think of a safe way of handling password recovery, we will change/improve the above features. At the moment, simply please write to us (contact [at] spoj.sphere.pl) requesting a password change.