Everyone who signs up for an openid account will get a code for the open beta launch on april 30. They occasionally give out invite codes, but they're limiting the number to do controlled tests of the servers. I'm over there as raz0rgirl. I'd get a seed account if I had $200 extra lying around (I don't); however, the paid accounts are tiered and will have a lot of great options (price details here: http://www.dreamwidth.org/support/faqbrowse.bml?faqid=4).