Wirelessly posted (Mozilla/5.0 (iPod; U; CPU iPhone OS 4_3_4 like Mac OS X; ja-jp) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8K2 Safari/6533.18.5)
for surfing the web, the ipad. the iswifter app does a respectable job with flash content if you need to view something in that way. however, it all depends on your surfing habits. the macbook air is a computer, so what you are really asking is whether you need two computers or something different. i think you know the answer 🙂
go to bestbuy, buy an ipad (wifi if using at home/coffee shops/with your mobile hotspot or 3g if you don't have wifi access) and give it a try. don't forget to get some kind of cover to protect it. i think you will enjoy it, but if you don't, you can return it 🙂