The Mifi is a great solution for bringing a WiFi hotspot with you everywhere in the city and even in the country (depending on HSDPA/UMTS/GPRS coverage in your country). It's perfect to add 3G connectivity to your Archos, iPad, iPod Touch, Laptops and any other WiFi-only devices that you may have. In this video, I compare the performance and features of the two Mifi adapters that are available on the market, the Novatel Wireless Mifi 2352 and the Huawei e5830.
In this video, I demonstrate a VOIP call taken using Google Voice and Gizmo5 on my $249 Archos 5 Internet Tablet using SIPdroid or any other SIP VOIP applications on the Android OS. This is the vision where you just need a pre-paid 1GB or 10GB of bandwidth per month on a SIM card, just enter it in your unlocked Mifi device, make sure the right profile informations are entered using the control panel and that's it. You've just about got a full mobile phone replacement, but where you don't need to pay for voice minutes and SMS subscriptions any more.
Although eventually all devices will have built-in unlocked SIM card slots and modems, the Mifi solution is a really great temporary alternative, that connects on 3G all WiFi-only devices. When your city gets White Spaces, LTE or WiMax, you don't need to buy new devices, just buy a new Mifi.
If you travel a lot in Europe, this is a must have. Then find SIM cards for cheap pre-paid plans, for 5€ to 10€ and get Mifi internet access all over that city and country.
The Novatel Wireless Mifi 2352 that I got was unlocked beforehand, I don't know if there are online programs to unlock one if you happen to have a locked one. It can be bought unlocked for 214€ at moblix.hu and expansys.com.
I will post further test video of the Novatel Wireless Mifi 2352 once I get to figure out how to use some of the more advanced features. And at Mobile World Congress, Novatel Wireless advertised the functionality of installing applications on their Mifi device (see my video interview about it), to increase the functionalities. Such as hosting a little server in there on the MicroSD card, doing some file-sharing, file caching, GPS tracking and other stuff. The Mifi is the kind of device that I think all busses, trains in Denmark are getting installed to provide free WiFi to all people taking public transportation. If you own a taxi business, drive a bus, own a sausage stand, providing your customers with mobile WiFi is an awesome opportunity.
I bought the Huawei e5830 at the Three store in London for £49 with a compulsory £10 1GB/month first month pre-paid credit. I then unlocked it for 15€ using http://www.dc-unlocker.com/ (it can also be bought internationally from ebay.co.uk for around £80 unlocked) and I installed the latest firmware with full Control Panel, built-in Profile and other Router management features at: http://www.davidicke.com/forum/showthread.php?t=98318&page=2. Consider also I filmed the Huawei E5 version 2 (with faster 3G HSPA+ speeds support and a new display) at Mobile World Congress, see my video here: http://armdevices.net/2010/02/15/huawei-e5-2-mifi-at-mobile-world-congress-2010/