http://www.greatwallofvagina.co.uk/home (http://www.greatwallofvagina.co.uk/home)
This isn't a trans-themed installation, but I found it very moving, so I thought I'd share it with you. They sell a DIY kit, and I'm definitely considering getting one for "later"... :).
...although having read more closely, I note that some of the contributors are trans men and women, which pleases me even more.