Best locations in Fiji for 20 yr. olds on a budget!

Hello to all,
I will be studying in New Zealand for their upcoming summer and fall term and am looking to visit Fiji for about a week in February. I am 20 years old and am planning on traveling with at least one other girl my age - others may possibly join us. Since we are college students we are definitely on a budget and am most likely going to look into hostels. However, I wanted to get some advice on which locations in Fiji would be best for us. Beautiful beaches are the main attraction we're looking for but it would be fun to meet others around our age range as well as other activities such as snorkeling, ect.

I look forward to some of your responses. Let me know if you need anymore information.
Thanks,
Giselle

Yasawas. Get a Bula Pass with Awesome Adventures and then book your accommodation on your own. The dorm rates at most places are pretty reasonable for what you get, and you'll meet many backpackers along the way.

The mainland is cheaper, but the beaches and snorkelling are garbage.

I'm in a similar boat - looking for cheap stuff - and the 5-night plan I put in the following post is going to cost me about $500 USD: http://www.lonelyplanet.com/thorntree/thread.jspa?threadID=2131392 I like the idea of seeing some of the mainland, and everyone raves about the Yasawas, so I think my plan packs as much stuff into a small time period as possible.