For a Monday update and analysis, go here. 
SATURDAY UPDATE Three polls, even the normally unfriendly Rasmussen, all recorded clear "bumps" for Obama today, with Gallup and Reuters-Ipsos providing more clear evidence of a DNC bounce. Consensus finds Obama with healthy 4% lead right now. See report and links here. 
LATE FRIDAY UPDATE New Reuters-Ipsos poll tonight  joined Gallup in finding an Obama bump from the DNC. It had not seen much before, but today revealed a 2 percent spike for Obama, and a 1 percent decline for Romney, along with some favorable metrics for the president, up about 4 percent. Obama now leads there 46 percent–44 percent. They suggest there could be more gains tomorrow.
Gallup, as usual, posted its latest poll findings  at 1 pm—and found a big bounce for Obama from this year’s convention, adding to yesterday’s indication . They show a very strong one-day 3 percent hike in his approval rating to 52 percent—his highest mark in many months. This means that he gained a whopping 7 percent in just the past three days.
Also, for the first time in more than a week, the numbers on his contest with Romney moved.
It had been a 47 percent to 46 percent lead for him (with no change at all from a week ago during and after the RNC)—but now he has opened lead to 3 percent, at 48 percent–45 percent. And that’s in a seven-day poll average with only the first couple days of the DNC factored in, so it should go up a bit more over the next few days. (Note: Gallup site erratic, probably due to heavy traffic right now.)
Here’s an item  on the results the past two days. By the way, Gallup has often lagged behind other polls showing leads for Romney, so a Democratic bias seems very doubtful.
Greg Mitchell’s books and e-books on influential American campaigns include Tricky Dick and the Pink Lady , The Campaign of the Century  (on Upton Sinclair’s 1934 race) and Why Obama Won.  He also blogs daily at Pressing Issues.