I would love to have a constant Internet connection from my commute in and around Greater Manchester (mostly), however 3G isn't always consistent for me which is why I went for the WiFi only as I tend to carry my iPhone around for anything important requiring net access.
I may have to get one of those MiFi things!
I have a MiFi, it's great.. I have my laptop and iphone paired with it. I also unlocked it so I can put any SIM I like in. So when I travel abroad I just buy a PAYG SIM at the airport and stuff it in. No more roaming data charges on my iphone for me!!!