I believe you can have concrete poured by a concrete company. They use a big pipe and pipe it through a window, if you have a window to the basement. I have the same setup - a basement with a dirt floor. I am slowly doing it myself, however. My original intention was to put a stone floor in - like flagstone, because I thought that would look really cool. However, a friend of mine gave me some salvaged outdoor tile - about six inches square, and very thick - they are sort of like salatillo tiles but much sturdier. Almost like thin bricks. I thought that would make a very nice looking floor, so I leveled out the dirt floor and put the tile down, using mortar mix underneath them. I could have used chicken wire underneath it, or that stuff that is like plastic (they use it for envelopes), or maybe I could have used sand underneath the tiles instead of mortar, but I didn't. We do not have a problem with moisture in our basement. After I had all the tiles down I grouted them together and then put grout finish on the grout and tiles, and it looks really good. I did have a bit of cracking in some of the grout, but I fixed it with some Welda Bond glue (I love that stuff). Even if the mortar and/or floor "settles" a bit, there is no place for the tile to go! In the next room I am thinking of self-pouring concrete and embedding moisaics with pebbles. There are so many creative things I could do! This may not be the answer you are looking for. I think just plain concrete is so bland . . .