If you normally just boil 2 cups of water, the Snow Peak 3-piece titanium cookset is worth considering, but it's expensive at $50. Leave out the smaller of the two pots and it weighs 4.7oz. The larger pot by itself without the lid is 2.5oz. If you don't use the lid as a fry pan, you could make a light one from foil or an aluminum cake pan.

DustinV mentioned the Trangia kit. It's kind of neat, but not super light. Mine weighs 12.5 ounces, and needs an additional windscreen in the slightest breeze. The pot's a little larger than the Snow Peak set, though.

Evernew also makes some good Titanium cookware. I have the 1.3L pot with the regular lid, but they make it with a fry pan lid too, and also a smaller 0.9L version. When I bought mine, it was $35...I see now they're more like $75! I like the silicone rubber tubing on the handles so you don't need a pot holder.