I see these on ebay, and are listed as new, but am not sure what unlocked means? What benefit does it carry and will that mean there is no longer a warranty?

It means it is a 3G model which is not locked to any particular mobile / cellular carrier. So you can use a SIM from any carrier supporting a data plan on the iPad.

Unlike phones, it is absolutely normal for the vast majority of iPad's to be carrier unlocked. It's really nothing special so make sure you are not paying a premium for it being unlocked.

The unlock status has absolutely nothing to do with warranty. That will depend on the age of the device like normal.

I'm not sure I understand something. When choosing an iPad 2, I will have to specify AT&T or Verizon as the carrier. Are you saying that I could buy, say and AT&T model, then use any carrier that has a data plan?

Originally Posted by donnyb

I'm not sure I understand something. When choosing an iPad 2, I will have to specify AT&T or Verizon as the carrier. Are you saying that I could buy, say and AT&T model, then use any carrier that has a data plan?

Basically, yes, any GSM carrier with the right plan.
Just make sure you do not go for the CDMA (Verizon) version, as you can only use that with Verizon in the USA AFAIK.