Our backyard is covered with this weed. It is something that is very
common in Austin, as I also see it in other yards and all around the
hike & bike trail. After the recent rains, it just went crazy. Here
are some photos of it, at a baby stage. If someone could tell me what
it is, I would much appreciate it.

Link to photos in gallery (click on thumbnails for larger versions):

http://gallery.me.com/gdmedia1#10021...or=black&sel=5

thanks,
gary / austin