gistfile1.js

// Idea from http://dbaron.org/log/20100424-any

jQuery.expr[':'].any = function(el, i, match) {
    return jQuery.find.matches(match[3], [el]).length > 0;
};

jQuery('body :any(div, form) p'); // Same as jQuery('body div p, body form p')

jQuery('div:any(.foo,.bar)'); // Same as jQuery('div.foo, div.bar')

Good point, @beverloo. The jQuery selector syntax has helped me better understand CSS. Syntactic sugar isn't enough of a benefit to justify moving away from the standard.

A different approach — http://twitter.com/padolsey/status/119790781417537536:

$.expr[':'].matches=(function(_){return function(el,i,m){return!!_(m[3]||'*',[el])[0];};}($.find.matches)); // CSS4 :matches selector for jQ