I just started using it out of dissatsfaction with my employer's server (too much spam, the web interface I am using while confined to Mrs Ethnia's computer is offputting), and kind of like its clever design. They have given me three invitations for new accounts to hand out. If you want one, just send me your e-mail address to [eastethnia at gmail dot com], and I'll send it to you. First come, first serve.
Update: They are all handed out. And interestingly, all to people in the same city, which is not the one where I live. But if I get more to hand out, I'll make a new post.