Sprint has a cool new hotspot that supports 10 users, supports 3G and both 4G Technologies (WiMAX and 4G LTE) and has a larger battery as standard equipment. You can read about the new device at:
Sprint Sierra Tri-Fi Hotspot (3G EVDO/4G WiMAX/4G LTE)
The Sprint Sierra TriFi hotspot also has an accessory called the Tri-Fi Desktop Cradle, which keeps your battery charged and also includes a built-in antenna (in the cradle) that improves signal on WIMAC, 3G and 4G LTE. The cradle sells for $59.99.
Sierra Wireless Tri-Fi Hotspot Desktop Cradle