These 3G USB modems have been discussed a number of times here. One of the biggest problems is that they suck power. I don't know about the E169, but the E220 needs at least 500 mA, which the N8x0 can't provide. So, to start with, you will need a powered hub. At that point it looks simpler to me to use a 3G phone with BT, if it's feasible for your area (and I know - it can be tricky business in the US due to those silly carrier constraints over there. In Europe it's usually easy though.)