The Giants acquired outfielder Jose Guillen from the Royals for a player to be named later and $250K. The Royals, who gave Guillen an ill-advised three-year, $36MM deal in December of 2007, designated Guillen for assignment on August 5th. The $250K is about $138K more than the pro-rated portion of the major league minimum salary.
Guillen still has $3.39MM left on his contract, but the Royals are covering some of that, according to a press release. The 34-year-old is hitting .255/.314/.429 on the season with 16 home runs in 437 plate appearances. He has logged only 169 innings in right field, so playing him regularly in the outfield would be risky. The Giants probably don't have an everyday role in mind for Guillen anyway - there's no reason he should supplant Pat Burrell, Andres Torres, Aubrey Huff, or Travis Ishikawa.
Enrique Rojas of ESPNDeportes first reported that a deal was close and Ken Rosenthal of FOX Sports, Ed Price of AOL FanHouse and Henry Schulman of the San Francisco Chronicle also broke elements of the story (all Twitter links).