This one comes from Kevin Powell, on a YouTube video short <ahref="https://www.youtube.com/watch?v=IQT4aI_Iup4">"Gradient text with CSS | CSS Tip of the Day"</a>. It applies a colored gradient to text.
Note that the -webkit- is needed to make this trick work in Safari.
<h1class="gradient-text">Thingy Text thats with a gradient</h1>