Here's rolling coverage of the live chart that 6-ABC in Pennsylvania is airing of undecided voters' ratings of the candidates during the debate. For live video, paste this in Windows Media Player.
A lot of the numbers are just a reflection of how much uninterrupted time a candidate gets, as the chart tends to float upward gradually. Most of the 60s are shorter answers. Also, Clinton is doing a good job of pivoting from the controversial questions to crowd-pleasing issues, and gets high scores when she does.
The final "Who won?" question is Clinton: 50, Obama: 23. They asked Clinton's Ed Rendell who won, and he first said ABC sucked, then that Clinton was far and away the best.
Picking the other as veep:
Obama's high: 65%
Clinton's high: 65%
Bittergate:
O: 67
C: 69
Obama's electability:
C: 72 (on and after "Yes, yes, yes.")
O: 75 (on "Clinton learned the wrong lessons" on baking-cookies-gate)
C: 65 (in response)
Pastor-gate:
O: 68
C: 69
O: Low of 47, high of 67
O (on further questioning): 62
C: 61
Clinton's credibility:
C: Low of 38, high of 51
O: 77
Flagpin-gate:
O: 73
O: 77 (on further questioning)
C: 63 (on response to question), 80+ (off chart on "Republicans shouldn't run anyone")
O: 70
Bringing troops home:
C: 74
C (on further questioning): 79
O: 72
O (on further questioning): 68
C: 77
Raising taxes:
McCain (via tape): 48
C: 78
O: 76
Capital gains taxes:
O: 73
O (on further questioning): 67
C: 76
C (on further questioning): 70
O: 67
Social Security:
C: 79
O: 64 (brief)
C: 62 (brief)
Gun control:
C: 74
O: 65
C: 64
C (on further questioning): 60
C (on further questioning): 64
Affirmative Action:
O: 66
C: 79
Gas prices:
C: 80+ (off chart)
O: 71
Using GWB in their administration:
C: 68
O: 71
Convince supers that you're more electable:
C: 72
O: 68