I really want to share my localhost over the internet to show my friends the progress of the website we're working on, so that I don't need to upload it to the public server each time I make a change.

showoff.io is not free and localtunnel gives me "failed to authenticate" when trying to upload my public key (a lot of people seem to have this problem and there doesn't seem to be a solution for this).

Does anyone know any other free service I can use or any other solution at all? I'm using a Mac.

Thanks.

UPDATE: with localhost I mean a web server running on my computer, I have a dynamic IP address and no I'm not behind a router (just using a wireless modem).