Minify your HTML by removing all the unnecessary characters.
Minify your CSS by removing all the unnecessary characters.
Get the gravatar.com globally recognized avatar for any email.
Get approximate IP details.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Ping a website, server or port..
Make sure your passwords are good enough.
Check for 301 & 302 redirects of a specific URL. It will check for up to 10 redirects.