I would very much like to get a wedding gift to give to my fiance on the day of our wedding in Kauai.

Does anyone have any great ideas? I would like it to be something to remind us of our honeymoon and would like to spend between $100 - $300.

I forgot to add. He is not into wearing jewelery.

I know you said your fiance is not into wearing jewelery, but one thought: I had the inside of my husband's wedding band engraved with a sweet sentiment (as a surprise) and gave it to him during the ceremony. He loved it!!

Something small made out of koa wood... a frame, box, clock or keepsake.

Islandmom has a good idea. My husband LOVES the wood in Hawaii and treasures a koa box we got there - not cheap but less than $300. It has inlay and special hinges. He could describe it better than me as he is a woodworker...
Is your fiance into music? My husband wants a ukulele this next trip.

Seriously, just greet him with a smile wearing just your birthday suit. It will be a gift and a memory he will treasure FAR longer than any trinket you could get him.

I second the idea of Koa wood. My boyfriend, and now husband, surprised me with a box made out of Koa wood and inside the box was my diamond engagement ring! It was truly a surprise!

Another idea would be a print from a Hawaiian artist. We have collected several originals as well as prints of our favorite places in Kauai and Maui.
We enjoy them year-round in our mainland home.

....or a print from a Hawaiian artist, framed in koa!!

There is some spectacular photography available of special sites in Hawaii. A framed print of a favorite place, maybe (signed by photog from a gallery)?

How about 2 beautiful wine glasses etched with Hawaiian flowers that you can use to toast each other at your wedding and on each anniversary to come?

And check out http://www.hawaiianislandprints.com/artist.html
The artist, Shayna Baecker Magid, makes Hawaiian Wedding Certificates that are unique and beautiful. Something to remind you of your Hawaiian wedding forever.

Nancy..I just checked the hawaiianislandprints website and you absoultely must have one of the wedding certificates. They are beautiful. Go ahead and get him another gift if you must, but treat yourself to this.
BTW, congratulations on your upcoming marriage.
I have followed all of your posts for months now and it seems you are going to have a wonderful wedding and honeymoon.