Thank you...these places are amazing to see in person. Waimea Canyon is often hazy (at least when I'm there), so if you have a SLR camera, you might want to invest in a circular polarizer - not to mention how dramatic it makes a blue sky and sunsets. Some minor touchup work to balance exposure, increase contrast and color saturation can sometimes make a hazy washed out photo look good.

There are alot of spots to view Waimea Canyon, so don't just follow the crowd...some great waterfall views are available on the road to Koke'e up from the Canyon viewpoint turnoff.

As for Kalalau - get there before 10am. This is my new mantra, as it took four visit attempts over the years for this fact to actually sink in. When the clouds fill the valley, it happens fast. 20 minutes after the photos in my link were taken, the valley filled with clouds and another 15 minutes after that, it was totally socked in at the viewpoint. When driving up from Koke'e, if you see blue sky at the military site near the top of the road, you should have an ok-to-great view. If you see fog or clouds there, it won't be good.

For the must-see sights, like Kalalau, leave time in your itinerary to go back in case bad weather washes out the view.