Aloha! My wife and I will be in Kauai for two days in June. What can we do to maximize our time there?

Every second counts when you vacation in Hawaii. Go to the beach, shop, and visit the Waimea Canyon in Kauai also.

http://www.hawaiiweb.com/Kauai/html/site...

Two days isn't much. Spend one day on the north shore - Hanalei & Princeville are gorgeous, some of the most spectacular scenery in the world. Spend one day on the south/west side, going up to Waimea Canyon & the lookout over Kalalau Valley. Fortunately, the island is small enough that it is not hard to drive from one end of the island to the other. So you could stay either in Poipu on the south, near Lihue on the east, or up in Princeville on the north & be able to see everything.

For such a short visit, your activities will probably depend on what end of the island you are staying in.- Poipu in the south or Princeville area in the north. Poipu tends to have sunnier weather, while Princeville and Hanalei have a more dramatic tropical rainforest atmosphere. I think a helicopter tour should be at the very top of your must do list. That way you'll get to see all of the island and soar over the Waimea Canyons (grand canyon of Hawaii) and the dramatic NaPali coast with grand waterfalls - it's an unforgettable experience. You should also get out on the water in a boat whether it's a dinner cruise on the NaPali coast, snorkel trip or maybe a kayak tour. Here's a compilation of adventure tour operators in the Hawaiian islands: http://www.wickedgoodtraveltips.com/?p=7...
Have a great trip.

Rent a four wheel drive vehicle and go on some trails, or on the beaches on the southern part of the island.