Can I install Ubuntu onto a USB flash drive using the SAME flash drive?

When you make a USB bootable with Ubuntu, it usually offers to either "Try Ubuntu" or "Install" into the hard drive. "Try Ubuntu" doesn't really save changes or treat the USB like a hard drive of its own. But that's what I want: a portable hard drive with Ubuntu OS installed into it so I can boot from it on any computer, and have all my changes saved. And yes, I have enough room in the flash drive (if 32 GIGS is enough).

I've read on Ask Ubuntu that this is actually possible by choosing your flash drive from the custom install menu (where it shows all the computer's drives, including sdb, the flash drive). However, the answer i read suggested that I use an Ubuntu DVD to make this work. Can I install Ubuntu onto a flash drive from that VERY flash drive itself? I've noticed that the "Try Ubuntu" interface still works even if I decide to unplug the flash drive, so perhaps the flash drive can install Ubuntu onto itself?

It's hard for me to word my question clearly, but I hope I did it well enough so that someone understands.

Thanks a ton :)

Booting to RAM, (toram), and unplugging will work, reference:

Can Ubuntu be installed to the pendrive it was booted from?

mkusb is superior to Unetbootin as it can make persistent partitions larger than 4GB, it will also make a NTFS partition from any excess space that is usable by Windows and Linux.

Edit: You can do a Full install of Ubuntu to USB using VirtualBox, Instructions at:

How do I install Ubuntu to a USB key? (without using Startup Disk Creator)

A simpler method:

Install VBox and guest additions

Make new Ubuntu virtual disk

Start disk and point to Ubuntu iso

When process gets to try/install screen activate target USB and select install

When process gets to partitioning select "Something else"

Select the USB as target and continue installation.