From the For What It's Worth File...

Zogby was polling during the Democratic Convention, and the results show that Democrats have at least (temporarily) achieved one of their objectives. 

Bush's job rating is at 44 percent, the lowest since mid-May.  Poll was conducted July 26-29, so impact of Kerry's speech isn't reflected. 

In the head-to-head, Kerry leads 46-41, increasing his spread from 47-44 in early July.  Not much "bounce" but again, no reaction to the speech yet.