Quick, while DH is distracted by Penn & Teller 
He turns 40 in a few weeks and would love an iPad but I have no idea what to get. He would use it really just for dicking about - internet, email etc. No real idea how all the various GB options translate
or whether you can add more memory eg with cards etc. Also have only a mild grasp on what 3G actually is - as I understand it, means you can get internet anywhere but you have to pay a contract fee (?). His phone is an HTC so can't do any clever synching with that afaik - am thinking wifi is probably enough so perhaps should get him lots of GB to make up for it?
Apple shop refurbished thingummies look good but wondering if there's somewhere better to buy. Also any info on the difference between iPad/iPad2 would be great.
Sorry if this all gets asked a lot
Any advice gratefully received!