You can stream from your computer.
Hardly. I just just checked prices (because I'm out of contract with AT&T and thinking of upgrading to a smart phone), and AT&T will charge me $130/mo for two iPhones while Sprint will charge me $128/mo for two Droid phones - and that's without the 4G tariff.
I don't see how you can price a comparable plan on AT&T for $130.
I have 4 phones on my family plan and everyone in my family would sure like an iPhone, but the value is just not there when you compare AT&T prices to Sprint.
You would have to find an AT&T plan that charges $40 for 2 lines since you need to add at least $90 in add-ons ($60 (2x$30) for iPhone data plan + $30 for family messaging) to match the Sprint plan.
The "Sprint Everything Data Family - with Any Mobile, AnytimeSM" get you, for $129/month:
1500 anytime minutes
free nights and weekends (7PM-7AM)
'unlimited' pda internet
Free anytime Mobile to ANY Mobile (this is huge!)
The closest similar AT&T plan would be the "Nation 1400 FamilyTalk w/Rollover® Minutes" plan, for a total $179/month and:
nights and weekends are 9PM to 6AM
free mobile to mobile only to other AT&T phones "from within your calling area".
Take a look at the Rich Ajax Platform Project.
Google Apps work without a broadband connection too.