Broken phone/contract dilemma?

I have an Alltell phone (now on Verizon) and the screen broke so it is still very hard (but not impossible) to read anything on the screen. I've had the phone since Nov. 2008 so its out of warranty but my contract is not up until this Nov. I took it to the Verizon store and they don't know how to fix it (which is reasonable since its not a Verizon phone) and they said I could buy a new phone at full retail or they would let me upgrade to a new verizon plan - which I do not want to do, I have not liked Verizon since they took over Alltel.

I could also use one of my old phones, but none have a QWERTY keyboard and I know I would miss that, and the two old phones I have I have used for 2+ years each and they've both seen better days.

I am 21 years old and currently an "added line" on my father's 5-phone plan, and he said I would have to get my own contract after this one expired, so I am only paying $10 (plus a moderate $6 texting plan that I always go over) per month.

I am thinking of swiching getting a new phone on Sprint. I want a blackberry or other smartphone and Sprint's talk/text/web plans are much cheaper than Verizon's talk/text/web plans (It would actually be a few bucks less per month to have the Sprint contract AND what I have now than it would be to have just a new verizon contract).

Money is not a huge issue to me, what do you think is the best thing I could do