This is an update of their previous offer. OzForex has recently been rebranded as OFX — new website, new sign up links, and new exclusive offer for the OzBargainers! Normally you only get fee-free transfer if you transfer > $10,000 on OzForex/OFX. If you transfer anything under $10k you have to pay $15 transfer fee. However if you sign up using this link you'll get unlimited fee-free transfers when you transfer over $250.
Referral
Do note that this might not work with the current Refer a Friend offer where both referrer and referees get $50 iTunes Gift Cards. You either get the OzBargain-exclusive offer (fee free transfer over $250), or $50 iTunes card. If you are usually transferring large amount overseas ($10k+) then maybe go for the gift card. Otherwise if you do frequent smaller amounts, OzBargain-exclusive would be a better deal.
Another thing — because they changed the URL the referrals, the previous OzForex referrals are scrapped and you need to enter in your new OFX ones to the OzBargain random-referral system.
Disclaimer
Similar to last time — OzBargain does not receive any kickback/commission from OFX. We are simply frequent users of OFX paying our overseas expense each month.
I have transferred money with OFX in the past, good service and better exchange rate than banks. This is based on a 1 off transfer but I personally would use them again.