It seems to me, in order to differentiate a new job website from what's currently available, a new business model is needed.
One way to bootstrap towards a critical mass of users would be to make use of Facebook and it's graph API. If you can convince people to use your Facebook widget/app, you could get access to their social network and their work/education/location information from their user profile. Facebook has yet to implement a Linked.in competitive service (although I'm sure it's being discussed), so this could be a way to bootstrap users for the time being.
Another idea comes from my impression that some people in smaller Hawaiian communities use the internet less frequently and in a more email-centric, technologically simple manner. Email newsletters are pretty popular in Kauai, and a lot of people learn about current issues/happenings through them. Just requiring a CC to some email parsing bot on a server would help a business ingest employment requests and opportunities passed around in a newsletter style email. I believe Lets-Trade Kauai (http://letstrade.vpweb.com/default.html) is another example of simple, but used technology (I'm not sure if there is a related email newsletter in this case).
Finally, I think there is also a significant demographic which reverts to bulletin board postings for employment and other sales/renting information. Finding a semi-wired connection to this community would get an additional untapped workforce. Although it's more grassroots than what you have in mind, weekly posting of employment requests and opportunities to bulletin boards using a flier might be useful. Aggregation of what's currently on a bulletin-board would be cool, but I haven't thought of a low cost, low risk way to do this.
How do you intend to generate revenue from this venture? My gut feeling is that the "casual worker" and companies looking to hire them probably won't be too keen on paying money to a website to either find jobs or post jobs. Monster.com makes money by charging fees to the companies posting jobs, and craigslist makes money in a similar way but only charging to large companies in the larger metropolitan areas, leaving it free for almost everyone else. General Internet users now expect most everything on the Internet to be free.
Also, since your hope is for this to eventually go global, or at least nationwide, you need to consider the fact that the domain name you've chosen, workhui.com, will have no meaning to 99% of your target audience.
I just wanted to say that I love your passion, drive, creativity and entrepreneurial spirit.
I have no doubt that, whether via WorkHui or some other venture, you will achieve great success.
Mahalo for your inspiration,