Answer:
Do NOT ask to be a mod! Please read the Newgrounds FAQ
New answer
Lots of people are wondering how te become a moderator or how they are chosen. It's not a matter of having something, like having more then 5000 posts or being a member for more then a year. No, it's a matter of your appearance in the forum.
'Real' moderators stand up on the first day they are here in the forum. They are doing something extra then the other member, they are helping other members, help thinking about how to make this forum better and they are here on a regular basis. If you look around you can find some these members. It are these members that earn the most respect from others and if a moderator is needed, these members are recommended for the job.
So it's not a matter of how much you have done or how long, but what you do and how you it.
Reference link http://forum.letssingit.com/topic/20313/how-to-become-a-moderator/1