Over the last three years we've seen screen sizes on smartphones vary from a smallish 3 inches to a massive 5.3-inch on the Galaxy Note. It's a similar story with tablets, only those started out at around 10.1-inches and have gotten smaller from there.
Meanwhile, despite longstanding rumors of Apple releasing a larger iPhone or smaller iPad, the company has stuck to its guns with the original 3.5- and 9.7-inch form factors of those devices.
I'm all for diversity and choice, but there's a point where a phone is just too big to carry around hassle free and a tablet is too small for the tasks it's intended to handle. We've asked the same question about laptops before, but now we want to know: What's your preferred smartphone and tablet size?
Personally, the 3.5-inch form factor of the iPhone suits me well, but I could easily get used to a ~4-inch device if it doesn't add much bulk. Anything over that seems unnecessary and would actually hurt portability. As for tablets, I think both 10- and 7-inch sizes are here to stay. So far I prefer the former.