I am using a vauum sealer of a brand called Maxkon, bought it years ago from crazysales: http://www.crazysales.com.au/vacuum-sealer/
Is anyone familiar with it?
The model is kind of like the one Soft71 mentioned, inbuilt roll holder, and with 2 rolls of sealer bags as freebie when I bought it. It works well and I use it to preserve hops and leftovers. And I want to say sealing hops is one of those aspects that keep hops in optimal condition. Temperature should be considered too. The lack of oxygen and low temperature can effectively slow down oxidation. And don't skimp on sealer bags, because you don't want extra oxygen penetrate the bag and spoil the lovely hops, right?