Hmm Fred's link doesn't seem to go anywhere after the first page.
I believe it is possible to dual boot 98 and ME, but you would need a 3rd party too like System Commander, widely regarded as the best dual boot manager. See
http://www.v-com.com/product/System_Commander_Home.html.
But frankly I don't understand why one would want to. There is very little value in Win Me to go thru the hops necessary to dual boot it.