well i am facing the same dilemma this poster has/had. Yet, mine is more specific. The i3-330m has 1gb discrete graphics memory,while the i5-430m has 256mb of discrete graphics memory.The i5 is $100 more,so i am stumped as which to choose,faster processor or more discrete graphics memory. This laptop will do mostly converting of HD movies and Web surfing and music/movie viewing,Bittorrent stuff too.
I would suggest getting the i3 model, since you can most likely upgrade to an i5/7 cpu in the future if you need additional power, while you can't generally upgrade graphics cards.
The performance difference between i3 and i5 is fairly inconsequential if you don't do anything too computationally intensive, but you should be aware that if you do indeed perform some computationally expensive task on the computer, and it does not receive adequate cooling (such as if you block off the air vent), the core i3 model will throttle itself at about 10 to 20 degrees earlier than the core i5 model, which will result in a fairly large performance hit... although if you're not adequately cooling it, the i5 will probably throttle itself a few minutes later anyways.