[leprycoon]

Mine was the same way. I tried everything including going to sprint to fix the problem. They just did a hard reset and sent me on my way, no real work involved. My phone would also sometimes three way call the person I was trying to call so I would have them and their voicemail on the phone at the same time. I rooted my phone and it all went away, the lag, the three way calling, and the periods of time where no touch input would work. As everyone has said though, it may be phone to phone, and rooting may not solve your problem.