Want to buy best UNLOCKED droid phone, but can I D/L apps?

[lawlington]

I can't afford a plan with at*t because I don't have the money to pay 60$ a month. What I do is go into best-buy and get Pay-as-you-go phone for 10 dollars, take the sim card out, and put it in my iphone (current phone, but broke and want the best of the best). So can I just put my at*t sim card *pay as you go, works with multipule i-phones) and will it work?

Why wouldn't everyone get unlocked phones? it works all over the world (all networks), but what I want to know is what are the restrictions. I know I have to pay like 400$ for the phone instead of 0$ with a plan, but I love my 2 dollar a day unlimited talk (and i only use it certain days) and I can buy 1000 texts for 10 dollars, (I usually text) so I save a ton and end up paying 20 a month for my iphone. So if I get this unlocked phone (any android phone), can I still download all the cool apps and go online etc? (I can buy data online at at*t payasyougo and it lets me go online with iphone), so is an unlocked phone the way to go? and can it d/l any apps I need? (get news feeds and stuff as long as I pay for the data plan at payasugo) ? On my iphone I can browse the web, but I can't download apps or access the marketpalce or any of the online-apps that came with iphone before I had the plan, but with millions of apps there have to be non-copywrighted ones I can just download? Like a facebook one and I can check it online? or would this not be possible, and if I wanted to get a plan in the future would I be able to? Thanks.

Oh and what would you recommend for the best phone running android, all I care about is a big quality screen and at least 720p recording.

Thanks!