I don't think Localtunnel can, but PageKite will carry any TCP stream as long as the client knows how to prefix its request with an HTTP CONNECT preamble. This has mostly proven popular for remote administration via. SSH, since most SSH clients can easily be configured to take advantage of this: http://pagekite.net/wiki/Howto/SshOverPageKite/
We are also quite open to the idea of supporting other protocols, but it turns out relatively few Internet protocols are amenable to "name based virtual routing" (the same thing as name based virtual hosting, except routing connection streams by name instead of serving local content).
That's pretty neat. When I need to make a firewalled machine SSHable I typically set up an 'ssh -R' reverse tunnel to a VPS, and then do a two-step connect (ssh to the VPS, ssh to localhost through the tunnel). PageKite seems like it might be a more convenient way to get that up and running.
Obviously, I am biased, but I use this all the time.
It's just so nice to be able to use ssh and rsync and git and all the other standard tools to interact with mobile and virtual devices, no matter what kind of network connection they have. The .deb/.rpm packages just make this feature part of the OS as far as I am concerned.