Wi-Fi has become broadly acepted, which is why even accessories that used to rely on USB have started to employ the wireless connectivity technology.
Fantec has released the MWiD25 which, quite simply, is a Wi-Fi portable drive enclosure that can hold 2.5-inch SATA HDDs or SSDs of up to 1 TB.
That means that any drive in 320 GB, 500 GB and 750 GB is fair game as well, provided they aren't thicker than 9mm.
There is still USB 3.0 support though. Mostly, it is there to secure the case to a standalone host, while phones, tablets and whatever else use 802.11 b/g/n WLAN or 10/100 Ethernet.
Companion apps for Android and iOS are available. Finally, the 3,000-mAh battery should last for hours before needing a recharge.