"Jobby job" comes from the video for "Gin & Juice". As Snoop Dogg's dad heads out for the day, leaving young Snoop alone in the house, he admonishes him,
"Snoop Doggy Dogg, need to find a jobby job! And don't be messing with my 8-tracks."
Want to feel old (or young)? Most of the college kids allegedly throwing this term around these days were about 10 when that song came out.