During the last two weeks of 2010 some strange colored goldfinch showed up at my feeders. I sent some pictures to several experts and they confirmed they were Lesser Goldfinch. They are not common birds here, but I now have six feeding with the American Goldfinch on the nyjer seeds.
In this first picture the Lesser is on the right while the American in on the left.
Here a Lesser stays on the seed sack after all the others have flown, allowing me to get within two feet of it.