Vodafone - GALAXY NEXUS $29 + $5/month on 24 month contract (+$100 cashback)
Usually it is $29+$16 per month, but you get $15/month off on mobile handset repayments if you sign up by 29th February; saving you a total of $264!
But that's not all...
If you purchase via the Buckscoop link, you should also be eligible for an extra $100 cashback.
I am not sure if you could also use the 10% off SAVE10 offer for existing customers (but you need to obviously get a new plan and new number on top of your current one) but if you can, that's an additional $69.60 off.
The phone is $716 paid over 24 months with Buckscoop cashback
If you are also eligible for the 10% off with code save10, it brings the cost of the phone down to $646.40 paid over 24 months.
Edited to add:
this exact same offer is also available for the Samsung Galaxy SII
Obviously the Galaxy Nexus is a better deal as this one is only a savings of $120. Also the nexus is a newer phone =) I'm waiting for the galaxyS III to come out ;D