Couldn't help myself, dove in for a rewatch. Time to pick up on all the little sight gags!
The murals at the Phoenix airport when Michael is riding the moving sidewalk show all the major plotlines from the first three seasons.
When Lucille 2 writes Michael the check for $700,000 (dated 5/1/08), the previous two entries in her check register are $800 to a party supply store for "cinco garbage (sombreroes and marionettes)", and $325 to juice boxes, "legitimate grape, snappy/apple/sugar cane plus".
The news report about Boy George is covered from "Actual Britain" by wee BBC 2.