/usr/bin/openssl won't let you create a certificate without a password (at least not as far as I can tell). That means that you can't create a test certificate to install on your Web server which will allow the Web server to come up with SSL enabled without stopping at boot time to prompt for a password. This is bad.
The default mode for the openssl "genrsa" command does not encrypt the key. To prevent encryption when generating a key while generating a certificate using the "req" command, use the "-nodes" flag: openssl req -new -newkey rsa:1024 -nodes -keyout /tmp/server.key -x509 -out /tmp/server.crt -days 365