1.) Make your own server via spare comp, bought up internet connection.
You might not need a terribly fast one if you intend to keep this strictly local, so DSL or Comcast (default subscriptions) should do.

2a.) Utilizing the trust low-tech solution of offline marketing, post flyers, pass by word of mouth in the community, etc. to those in your locale that you wish to know about your site.

2b.) Here's the catch: when you inform others of your site, tell them explicitly that your site will only be online from Hour A to Hour B (i.e. 8PM to 10PM).
They will require any of the following; login info that you provided for them, a keyword to say upon entering the chat room, a certain thread to post in on the BBS, etc.
Use your imagination with this one.

3.) Repeat & vary the process, keeping your local site online only when needed or desired.
For the days that you don't want to filter access, utilize all the traditional methods of blocking outsiders out.

Not a perfect solution, but it's another tool to use rather than just whitelisting (blacklisting is less effective).

(in order of usage)

notepad2 (WinXp / WINE / Linux)

I've weaned myself off of windows considerably, but I every other month I'll use WinXp, & somehow manage to do most web design during these times. I prefer notepad2 due to nostalgia, but I also find it the gedit equivalent on WinXp. If it had a classic mode (notepad orginal), it should replace notepad entirely.

gedit (Linux)

Gedit is probably the only app I've encountered on linux that instantly replaces a windows app I used extensively (decibel audio player almost comes close in replacing foobar).

A joy to do what web design stuff I do on ubuntu, but has mainly been used while configuring openbox & attempting to learn programming (in order of progress: php, ruby, python, & javascript)

nano (Linux)

This is recent but significant, as I use it whenever I'm on Xubuntu on the old laptop I have (less than 192 mb of ram; n'uff said). I will probably use nano & gedit more often when I get to installing #! (CrunchBang) on my main comp, & sort out my partitions.

Nano pulls up hellafast w/ sakura (terminal) compared to gedit, however, so it most suited to quick copy & past operations, methinks. Leafpad is a good analog, but I prefer Nano regardless.

Runner Ups:

notepad++ (WinXp)

I used to use this at work until I installed notepad2. I just prefer notepad2's UI over this otherwise competent replacement.

vim

I've tried it before but didn't really like it, sorry :\ It gets included anyway for it legendary status though. Perhaps I'm just not l337 enough to appreciate it.

I'm going to explore more non-graphical text editors, though, so I'm sure this list will change at some point.