Minify your HTML by removing all the unnecessary characters.
Minify your JS by removing all the unnecessary characters.
Generate passwords with custom length and custom settings.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Check if the URL is cached or not by Google.
Make sure your passwords are good enough.
Take an IP and try to look for the domain/host associated with it.
Get approximate IP details.