I know its new account creation is turned off. But, I was able to contact the owners of a few other "no new accounts" projects via email and ask them to let me in. But for TN-Grid, I don't see any contact email address on their project site to make such a request; maybe I missed some tiny footprint somewhere. And, without an account, I can't post on their forum to ask them. If anyone that actually owns or knows people who own TN-Grid see this post, I would very much appreciate a way to contact them. Feel free to PM me.

Thanks
Tuna

Yep, it seems like there's no contact e-mail on the web page. Try something like webmaster@dsi.unitn.it or admin@dsi.unitn.it.
Anyway it doesn't seem like they are going to need more testers until the beta phase is over.

Thanks!