Well I use my tablet which is wifi only if I am going to do any on the road editing/etc. IT can use SplashTop to connect to my Mac at home, but since it has Polaris installed I am usually all set. To use my smartphone I would need carry a keyboard and mouse, and at that point might as well just use my Asus Transformer and keep the phone free to do smart phone stuff.
Not had a need to use 3G on my tablet yet, wifi is available so many places now. I could get a tethering plan... but rather save the $$.