Available Wildcarded DNS Domains
It turns out that some kind hearted people already set up wildcarded domains for you already. You can use any top level domain below and any subdomain of these and they will always resolve back to 127.0.0.1 (your local machine). Here's the list of ones I know about. Let me know if there are more!
*.fuf.me- Managed by @fidian; it will always point to localhost for IPv4 and IPv6
localtest.me- Also has an SSL cert - see http://readme.localtest.me
*.local.sisteminha.com- Managed by @tinogomes