Squaretrade is a great company, I highly recommend them. Last weekend I dropped my iPhone in water on accident which was a Sunday. I went online and started a claim that day. Monday, a rep called me to discuss what happened and he emailed me a UPS shipping label. I printed the label, placed it on a box and packed up my broken iPhone and shipped it off late Tuesday afternoon. On Thursday I get an email saying my claim has been approved and they are going to Paypal me $499.99.
Very quick process, friendly rep (I assumed I was going to get scolded since I had a claim so close to when the 3GS came out, even though I'll never go back to AT&T again in my life so no iPhone for me).
I talked to the rep a little more and it sounds like liquid damage is replaced without attempting repair. He said things like broken screens a lot of times they can repair and overnight the phone back to you with no problems so they do decide if they are going to repair or replace. They never replace with another iPhone, they just send you a check so you can spend the money however you want.