I didn't have any jerky issue after adding the psb drivers to the kernel, I could make a youtube video if you want to something to compare.

3G INSIDE the netbook... sounds cool, I have no idea if it has an interface for that.

I've been trying to get my Iphone to do internet tethering via bluetooth at lunch time, but it didn't work out of the box, not sure if I'll try again.

I know my boss once had an USB stick for mobile internet via GSM/UMTS, I once put it in an Ubuntu (normal Ubuntu, Intrepid) laptop and it got recognized and worked immediately. I think that would be the simplest solution if you want mobile internet.