Silver medal in the Graph of the Day contest (we'll have the gold medallist up on Coffee House later) goes to this effort from YouGov. It's just been published, with details, over at PoliticsHome, and tracks public "buzz" about the three party leaders during the course of the campaign. I'm not sure how much to read into it, but the peaks and troughs do follow the contours of the election - so Clegg's support rises after the first TV debate, Brown's plummets after the Gillian Duffy incident, and Cameron pretty much flatlines it. One striking feature is how much ground Brown has caught up since last week: the last few days really have been his best for some time. Not that any of this will really matter after tomorrow.