Tethering, and general Alltel questions

I'm looking into getting a new plan either through Alltel or Verizon(Best coverage where i live)
One of the main things i want is Unlimited Internet use, For instant messaging,ect.
And i was wondering how Tethering works through Alltel.

I was going to get a Basic 'Nation Plan' for $39.99 then add Connect pack 4 Or 5
for the Unlimited Text and Unlimited Data minutes, But I'm not sure if that would allow me to tether the connection or do i need a voice and Data plan to do so.
so i was hoping someone could explain that too me.

Also i wanted to know if Tethering is specific to Computer use only or if i could for instance tether the connection to an XBOX 360 or PS3 or some other device that isn't a computer directly.

And does anyone know if you can actually use a Smart-Phone for the nationwide plans. I know it won't let you on the site, but if i was to buy a HTC Touch off EBAY and then went into the store to get it activated would they allow it or would they force me to get a Data and Voice plan?
Because i like the looks of the Glimmer and the Rhythm and they have nice features to them they just aren't quite what i was hoping to be forced to use.

Also on a side note does anyone Know if the Pantech Duo or Matrix from Sprint is compatible with Alltel service. They are both CDMA services but thats about as far as my Knowledge of there systems goes.
Thanks in Advance

 

Thank you both, very much.