Website uptime monitoring and instant site availability check from a number of locations worldwide. Shows the result, the response time and page loading speed of any given web page.
http://host-tracker.com/

A PNG optimizer that actually works, even if you have saved your PNG through a professional image software, such as Photoshop prior to that.
http://www.punypng.com/

Smush.it optimizes image files. After Smush.it runs on a web page it reports how many bytes would be saved by optimizing the page's images and provides a downloadable zip file with the minimized image files.
http://www.smushit.com/ysmush.it/