has any body put freebsd on a drive smaller than 80megs?

From their handbook:

A minimal installation of FreeBSD takes as little as 100MB of disk space. However, that is a very minimal install, leaving almost no space for your own files. A more realistic minimum is 250MB without a graphical environment, and 350MB or more if you want a graphical user interface. If you intend to install a lot of third party software as well, then you will need more space.

here's the link

I've heard of a VERY small UNIX - where it has no graphical env - unfortunately, I don't remember where or when I had heard of it.

This isn't the one I was thinking of but....it may be where you want to go.

Linux Minimal configuration

3.1 Minimal configuration
The following is probably the smallest possible configuration that Linux will work on: 386SX/16, 1 MB RAM, 1.44 MB or 1.2 MB floppy, any supported video card (+ keyboards, monitors, and so on of course). This should allow you to boot and test whether it works at all on the machine, but you won't be able to do anything useful. See http://rsphy1.anu.edu.au/~gpg109/mem.html for minimal Linux configurations

In order to do something, you will want some hard disk space as well, 5 to 10 MB should suffice for a very minimal setup (with only the most important commands and perhaps one or two small applications installed, like, say, a terminal program). This is still very, very limited, and very uncomfortable, as it doesn't leave enough room to do just about anything, unless your applications are quite limited. It's generally not recommended for anything but testing if things work, and of course to be able to brag about small resource requirements.

PicoBSD will fit on one 1.44MB floppy...

Course,it rather, umm... shall we say limited...?

It can however work as a simple webserver among other things.

If your harddisk do not enough to Install Unix...You can use version of unix was burn on CD...

You can boot and use it direct from CD...