I am looking for a mobile modem that

* accepts a SIM card
* works on battery
* lets devices connect via WiFi
* is UNLOCKED
* works in Germany/Switzerland/Japan/USA

I found a few devices from Zoom (We3G), Huawei and Novatel. For Novatel I think only the 2352/3352 work in all of the above countries and these devices are quite expensive $190-$250. Huawei has many devices and looking at the description I am not quite sure which one will work in what country. The Zoom We3G right now looks most attractive as I think it meets all requirements and is inexpensive ($120).

Has anybody any experience with those devices, can recommend or recommend again any of them, or has any other input. There are almost no comparisons for those type of devices.