To be honest I am not clear on this topic. How can a desktop be useful for mobile browsing anyway? lol.
If you are on the go then
a- Smartphone
b- Tablet
c- Laptop
If you are at home then
a- Desktop PC
b- Laptop
If you are in the air
a- Smartphone
If you are in water
a- Water proof Smartphone
I think Tablets are a good balance between laptop and smartphone. They are mobile and more powerful. If you are into Apples then IPAD mini retina is a great one. If you are a android then Asus Nexus 7 inch is the best seller.