The MIFI is pretty flat. It is the size of a credit card? I don't think it is that heavy?

One of the advantages of the MIFI is that you put it somewhere (e.g. near a window) and then you connect to its WLAN (10 meters). If you are in a building with not so good 3G in some parts this can be pretty useful. I spoke with the guy who imports the MIFI to Europe (he is too zealous about his product but thats understandable). His example was that he'd be in a pub and put the MIFI near a window. Well, I, for one, would not prefer to put my mobile device out of my reach or even on table in a pub. I had to put my mobile device sometimes on a Nokia loader in past, and it just doesn't feel comfortable.

My main beef is the price. I find it insane. And probably, you cannot use the SIM to phone. What is interesting is that its build on Linux, so it has to be partly open source. It also has a lot of hardware not necessary for me. Such as GPS.

Some people have managed to get 3G working on USB lan, but you need a USB powered hub then. If you're more a static traveller (don't need to have 3G on battery) you might as well get a Fonera 2 then. This puppy also supports USB 3G sticks, and will use it as backup. You could use it in car too, together with the lighter power.

(As owner of iPod touch I must admit it might be interesting to combine, if I were interesting in using my iPod touch more seriously. (I'm not ))

In Spain and UK you can get MIFI with telco contact (subsidized).

The Huawei E583X (i-Go) should be sold too, it is competitor of MIFI, but I haven't seen it sold yet.