The other day Reggie Sanders hit his 20th home run of the season in the Cardinals 6-4 win over the Pirates. It was the seventh time Sanders had hit 20 homers in a season and assures him of his fourth straight 20-homer season. That's nice, but what's more impressive is that he has hit 20 homers a season with six different teams. He is the first man in baseball history to have achieved that dubious honor. He has also hit 20 per season in each of the last four seasons, each with a different team (Arizona, San Francisco, Pittsburgh, and now St. Louis).
Consider that as of today, there have been just 191 players in baseball history who have even hit 20 homers in six seasons, let alone with multiple teams.
By the way, here are the players who have hit 20 homers in a season for four or more teams (including 2004):