Subdomain on localhost

Question

I would like to create a registration form which creates subdomains (yet on localhost), but I have got some problem. I know how to create subdomains, writing for example the

Answer 1

http://*.lvh.me/ is an alias to localhost. Perfect for testing subdomains.

$ host lvh.me
lvh.me has address 127.0.0.1
$ host foo.lvh.me
foo.lvh.me has address 127.0.0.1

Edit: 2016/07: lvho.st went away, swapped for working domain