There isn't much talk about meshing WiFi and Cellular networks, yet more and more phones are coming equipped with the ability to connect to both. In a press release issued today, D-Link announced a technology they are calling “V-Click”, which will be integrated into a phone. It will allow the device to toggle between using GSM frequencies to unlicensed 802.11 frequencies. When GSM is unavailable or WiFi is plentiful and the user wants to save money on voice or data, it can be switched (manually) to 2.4GHz and pick up local APs:

With a simple press of the V-CLICK button, the phone activates or deactivates the Wi-Fi connection that allows users to access websites or an Internet phone service, and enjoy the convenience of reduced communication costs, faster transfer speeds and increased productivity resulting from dual-mode phone access.
City-wide WiFi and generic hotspots are popping up more and more, making this kind of device more useful than it would have been five years ago. No mention is made as to how this may impact the clogging of the 2.4GHz range, and it is entirely possible that future phones like this will be able to use 802.11a as well, using the unlicensed 5.3GHz and 5.8GHz spectrums. You can read the full press release in the comments section.