Not sure what you mean by "launch". My site XLEF.com was open to the public ever since I started it, even with some empty categories. Obviously, more surfers are likely to stick around when they see a lot of links, but hey, I am not keeping it hidden until then.
If you need clean freesites to populate your pages, feel free to grab any of mine here -
http://leesporn.com/freesites.html