For JG, my real initials

Junior Grade
Jeff Gordon (NASCAR driver)
JumpGate (Internet game)
Jetsgo (airline)
Junge Gemeinde
Job Guide
Journal of Geodesy
Jump If Greater
José Gil (Guatemala drugstore)
Junior Guards
Joint Guard
Jagdgeschweder (German: fighter squadron, Luftwaffe)
Juxta-Glomerular Apparatus (kidney)
Joe Genius (website)