LiveRamdisk is a pun at LiveCD, hinting that it must be something which allows users to try Linux easily without much preparation and that entire distro will be loaded from RAM.
For PocketPC case, it is a single big .exe file which when being started from normal WinCE environment, loads initrd (or a something alike) and kernel into memory and boots the latter.
I wanted to do something like that for a long time, and rejoiced when Kevin O'Connor, another HaRET maintainer, added ability to create single-exe bundle to HaRET 0.4 this winter. Unfortunately, nobody picked up this possibility, so I decided to give it a try, finally. Alas, it turned out to be not so easy when came to loading realistic (~20Mb) images. So, bunch of hacking was needed both on HaRET and Linux side.
But finally, first LiveRamdisk, an Angstrom X11 snaphost for hx4700, was released two days ago. Besides announcing it on Angstrom mailing lists, I also did some cheap PR on local forums. Well, two days later, the reaction is rather mild - there were only 3 downloads. At the same time, I was pretty surprised that my unofficial Familair 0.8.4 release for h4000 was downloaded 900 times in total. So, time will tell ;-)