Use the Google translator API to generate text to speech audio.
Get the gravatar.com globally recognized avatar for any email.
Extract email addresses from any kind of text content.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Check for 301 & 302 redirects of a specific URL. It will check for up to 10 redirects.
Make sure your passwords are good enough.