Short answer: you can't. Ports below 1024 can be opened only by root. As per comment - well, you can, using CAP_NET_BIND_SERVICE, but that approach, applied to java bin will make any java program to be run with this setting, which is undesirable, if not a security risk.
The long answer: you can redirect connections on port 80 to some other port you can open as normal user.
Run as root:
# iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080
As loopback devices (like localhost) do not use the prerouting rules, if you need to use localhost, etc., add this rule as well (thanks @Francesco):
# iptables -t nat -I OUTPUT -p tcp -d 127.0.0.1 --dport 80 -j REDIRECT --to-ports 8080
NOTE: The above solution is not well suited for multi-user systems, as any user can open port 8080 (or any other high port you decide to use), thus intercepting the traffic. (Credits to CesarB).
EDIT: as per comment question - to delete the above rule:
# iptables -t nat --line-numbers -n -L
This will output something like:
Chain PREROUTING (policy ACCEPT)
num target prot opt source destination
1 REDIRECT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:8080 redir ports 8088
2 REDIRECT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 redir ports 8080
The rule you are interested in is nr. 2, so to delete it:
# iptables -t nat -D PREROUTING 2
Best Answer
Your mysql database already has a root password. It was probably set when you installed mysql.
If you know the existing password, use this:
The '-p' will tell mysql to prompt you to enter your old password first. Then, it will replace the existing password with the string NEW_PASSWORD.
If you do not remember the original password, you'll need to shut it down and start it following the instructions at http://www.cyberciti.biz/tips/recover-mysql-root-password.html . This is easy to do, but does require some downtime.
UPDATE
Another option.
You can tell Ubuntu to reconfigure your MySQL server. This will reconfigure mysql-server-5.1 from scratch, and will ask you for a new password from the root user. Caution: This will completely wipe out any existing data, and will replace them with the default data. However, I'm guessing your database doesn't contain anything.
(If I remember right, Ubuntu 10.04 comes with MySQL server 5.1, not 5.0)