Although security on a Mac is debated heavily by both sides, I prefer to stay safe and use a standard account for my day-to-day uses, and an extra Administrator account for my, well, administrative uses. The thing that bugs me is that every time I log in, I see a this big login option, Administrator, and that easily tells someone that is physically stealing my notebook that he needs to crack the admin account, and not mine, to hack my system. I prefer to hide the admin account, but I don't really like to use the Terminal.
So, to the hint: from what I've seen, if you create an account named Administrator with a short name of Admin, the computer will automatically hide the account for you. However, this only works when the new Administrator account is the only administrator account in the system.
[robg adds: I tested this hint, and (somewhat to my surprise), it does work. Case matters, though -- make sure you capitalize the short name! In order to have the account auto-hidden, it does need (or so it seems at first) to be the only admin account. My first test failed, and that's because it was the second admin account on the machine. I then converted my standard admin account into a regular account, then created the new Administrator account. On my next login, the Administrator account wasn't listed in the login screen.
However, after logging in as the new admin, I then switched my standard account back to administrator and logged out. This time, the Administrator account stayed hidden. So it seems it has to be the only admin account when it's created, but after that, it will remain hidden if you add additional administrators.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20070529151159989