I've seen a command, which allows you to change your nickname... I think it was /nick...

Would be cool if it was implemented into HawkServ, because some of us (Like me) want a different username, and we cant change it via minecraft.net...

It would be an Admin Command, so that only Admins were allowed to change Nicknames, but they were allowed to change other people's nicknames...

Although it's an interesting command, it has too many security flaws for it to be safely implemented. Since most of HawkServ's functions use player names, it could easily be mistakenly typed as the username of someone else, meaning that they would get all the privileges that user has within the server. Spoofing nicknames also applies that users skin to the player.

WoM has a similar feature in its Direct Connect URLs, being that you can put anyone's name in there, and it'll give you everything as if you are genuinely that user. I've done it for a few other users in the server, and I automatically gained their rank. It's not safe at all.

TL;DR: Due to a security issue with Minecraft.net, this will not be implemented.