Yes, a seven-inch phone. When you hold the Nexus 7 in your hand, you realize that this the perfect device to replace both your smartphone and your tablet. Thanks to its improved form factor and non-slippery backside, you can hold it in your hand -- at least if you have large hands -- just like a large smartphone. In order to enable the LTE version of the Nexus 7 to also be a proper GSM phone, it would need to add some bands to its baseband chip from Qualcomm, some antenna and RF front-end components, and microphone plus speaker in the right place, just like every other smartphone. This would likely bump the price from $349 to $399. The current seven- to eight-inch tablets from companies such as Samsung and Apple currently make the big mistake of not being a proper phone as well. This forces the user to also carry a smartphone. Seeing as these devices (smartphone + tablet) are almost identical otherwise, it means that many of these tablets end up going unused after the initial honeymoon period. Basically, if you now have a five-inch smartphone (as opposed to a four-inch smartphone), you will end up reaching for the smartphone more than the tablet. However, if the tablet had the same full phone functionality, you would be using the tablet instead of the phone. People make fun of this concept because they claim people don't want to put a seven-inch phone up to their heads (ears). However, many people simply don't make that many calls -- but they must make some -- or they use Bluetooth or some other wired headset for frequent calling. They just need to put the device up to their head from time to time, and therefore don't care much that it's a larger one. The Asus Nexus 7 gets an almost flawless grade for what it is, especially in the upcoming LTE version. I just wish the Asus and Google product definition, management and planning people better understood where they needed to take the product to make it a far greater sales success than it is likely to become. Including full phone functionality in the Nexus 7 is not a difficult engineering exercise. It can be done and would add $50 to the consumer's price. It just needs the understanding by the product definition and planning people to see where the market is going. Right now this is virgin territory that is starving to be satisfied. The Nexus 7 would be the perfect seven-inch full LTE phone. At the time of publication the author was long GOOG, AAPL and QCOM.Follow @antonwahlmanThis article was written by an independent contributor, separate from TheStreet's regular news coverage.