Do you think technology has a positive or negative effect on society?

I can't help but wonder whether all these gadgets and gismos are really helping us to lead more valuable lives. Life online seems to be a dress rehearsal for the real thing, while new iWhatevers, such as iPhones turn novelty to boredom. It seems we are building an artificial mountain of expectation of improvement that won't be able to hold up forever, soon it will come crashing down. But this is just my opinion. What do you think?