PollingReport.com has a new feature: the National Trial Heat Summary, which compares several polls taken during the same period of time. It's a snapshot picture of a moment in time, rather than a trend tracker, so you can get a good view of the spread across all polling organizations. Its makes it really easy for us laymen to spot the outliers.
For example, today's snapshot shows a spread among likely voters as between -4 and +7 for Kerry (in 5 polls). It's easy to see that the -4 is way off, but there are two 7s and a five, so the numbers are definitely weighted on the higher end. For registered voters, the spread is 0 to +8 for Kerry (in 8 polls), with both the extremes obvious outliers.
Thanks Polling Report!