Some daily comic strips it pays to read with your full attention -- like Dick Tracy. Mike Curtis and Joe Staton frequently salt Dick Tracy with pop culture references and crossovers with other comic strips. They've even hinted that one Tracy's earliest foes, Broadway Bates, is actually a brother of the Batman's adversary, the Penguin.
This sequence beginning 2/10/14 ties Dick Tracy's world more closely to the DC universe. (click on images to enlarge)
Metropolis is Superman's home city, of course. But not as many readers would recognize Opal City, the home of Starman. Starman began in Adventure Comics in 1938, and although never a top-rank hero, is still around (albeit after going through various incarnations).
Opal City is also the home of one of the versions of the Black Condor and Phantom Lady, two early comic book heroes eventually brought into the DC fold.
Star City is (or rather was, before a continuity reboot) the home of the Green Arrow.
Connecting Dick Tracy to DC seems right. After all, those initials originally stood for the company's flagship comic book, Detective Comics.
(And yes, Bernard Fife is indeed the proper name of Mayberry's favorite deputy.)