The BBC has a map of Transparency International’s corruption perceptions index for 2009. Click the image for the related BBC story. Transparency international also has an interactive flash map (you can zoom in and see per country scores) of this year’s scores.
—Edit: Nov 19, 11:45am —
I friend asked me a good question about understanding the TI CPI methodology. The CPI aggregates the results of 13 separate surveys of business people or country experts. The CPI is subjecive, but bias should be lessened by aggregating the opinions of different groups of people. You can find a good .pdf file here that compares various indicators and indexes of governance and institutional quality.