The basic goal is to allow "generic" online guests to be able access to some server behind a NAT. For example say I'm hosting some images on a server behind a NAT, I don't have admin access to the NAT router, and uPnP is turned off. I would like to be able to send out an email to family and friends and they somehow access this image server without having to install any software first. Or I'd like to be able to run TightVNC and from any arbitrary internet connection be able to access the thing. I'm not worried about security at this point, just being able to connect at all.
Is there any way to accomplish something like this? Any projects that do this?
- TURN servers/NAT traversal (maybe there's some project that supports browser NAT traversal?)
- opera unite might actually be pretty close 
- http://leadthinking.com/89-machsend-p2p-in-the-browser does kind of naive NAT traversal on the fly in the browser, fairly naive.
- http://samy.pl/pwnat requires a local executable, not windows compat.
- openvpn has no browser client apparently  
- Hamachi requires a local client, seemingly.
- dropbox only shares files, same with windows live mesh (can be offline, though, which is good).
- allpeers is files only/dead
- 2peer requires a client plugin I believe, and is files only [?] -
Anything else out there? None seem to open an arbitrary port.
 http://www.labnol.org/internet/turn-home-computer-into-web-server/9111 mentions a few others, as well.