Anyone out there can you comment on the following:

Needs: PDA Phone with faster web browsing ability, I;m on the road most of the time and would like to check on FOREX Data and Equity Markets.

Selection: Sprint Audivox 6700 with Sprint Vision Plan for $15.00/month with voice plan of $29.00/month.

Question:
1. Which network is faster 3g or Edge or EVDO?

2. What is tethering?

3. What options do i have for the most economic choice of carriers and the best PDA/PHONE out there in the market place.

Looking forward to your expert comments/suggestions.

Thanks in advance
Gogetr