The following examples are all created with d3 and use svg patterns. Click on any of the examples to see the svg pattern definitions and copy them into your html. For reference, here's how you might use them with d3:
selection.append("rect")
.style("fill", "url(#circles-1)")
.attr("x", 0)
.attr("y", 0)
.attr("height", 150)
.attr("width", 150);