You can get a free roundtrip HNL-LAS if you fly 10 interisland roundtrips.
Ten to One Offer for HawaiianMiles Members Only
From January 11th through June 15th, every interisland flight you take on Hawaiian Airlines earns a 5% discount off the applicable Midnight Madness roundtrip fares. The more you fly, the less you pay. Apply your discounts to a roundtrip fare at any time between now and December 31, 2005 for travel between April 4 - December 31, 2005. Or accumulate your discounts toward a free trip. Just ten interisland roundtrips get you to Las Vegas and back. Taxes, fees and other restrictions apply.*
More,
here.
Also, special one-way Web fare on the early morning flight LAS-HNL:
Midnight Madness Flight 17
FROM Las Vegas (LAS) TO Honolulu (HNL)
(Applies to Flight HA17 Only and available as a One-Way Trip.)
4/11 to 6/09
Days of Operation:
• From 4/11 to 4/30/05: Mon, Tue, Thu, Fri, Sun
• After 5/1/05: Daily
$139*
FROM Honolulu (HNL) TO Las Vegas, NV (LAS)
This flight leaves LAS at 02:45 and arrives into HNL at 05:55.
More,
here.