http://placeit.breezi.com/
Useful tool for designers. It places a screenshot (any screenshot) into all sorts of devices: laptops, tablets, smart phones. You can browse the device gallery, choose your environment, drag-n-drop your screenshot and then save a PNG with it positioned on selected device. Pretty cool stuff for your portfolio!
http://wagerfield.github.io/flat-surface-shader/
Besides the fact that it’s simply crazy cool thing, you can use it to generate low-poly backgrounds for sites and so on. Adjust colors and lights and then click EXPORT to get a PNG screenshot.
http://sandbox.juan-i.com/longshadows/
Ultimate fashionable web designer toy! Generates long shadows in CSS3. Code works flawlessly.
http://www.alessioatzeni.com/meteocons/
Awesome meteo icons, which are also available as web-font. Free.