UNC’s Jim Stimson, the leading political science expert in public opinion time series data, has a running tally of presidential trial heat polls on his website that you should check out. Here’s the latest graphic — as you can see, it looks like Kerry is trending upward, though still slightly behind Bush:

It’s based on methodology he’s developed for combining polls that are only partially comparable and filtering the systematic component out from all the noise. Rather than getting caught up in tracking polls that are bouncing all over the place, check his page out instead – he updates it daily.