I've searched everywhere and can not find an answer for my question.

I would like a Blackberry on AT&T but since it will be only for personal use (i.e don't care about push email) I find it unnecessary to pay $30 for the BB plan when I can get an iPhone plan for $20. What this will be used for is - internet, text messaging, pix messaging, and voice... is this all possible using an iPhone plan for a Blackberry? Or does pix messaging require the BB data plan?

Wirelessly posted (my new touch button BB)

Officially no can't be done

However I have heard of people doing just as you are asking

I don't think the iPhone data plan will work, at least not very efficiently for Internet access. From what I have heard and read, it is pretty much hit or miss - you might get it to work or you might not. I think you would have a better possibility using a medianet plan. In any case, with no BB dataplan, you will need to use OperaMini as the browser, plus BBMaps and GoogleMaps will not work as those both require the BB dataplan. I don't think MMS will work either.

I don't think you will be happy with the BB if you don't have the BB dataplan. Don't be so cheap! Its only $10 more a month!

My Pearl would not work with the iPhone plan. The BB won't connect to the data side at all. I now have the BB personal plan for my Pearl, and it works with the iPhone also! Now, I can swap my sim between the two devices and both work perfectly.