Even musicians who aren't in Led Zeppelin have been known to apply a five-finger discount to musical materials on occasion...although their half-inching is usually a bit more subtle.
Here are some examples.
First up, I noticed this when it came up on shuffle at work the other day: the track "Town & Country II & III" by Ashley Park (I think they should have called themselves the Low Llamas) nicks part of its melody from the Beatles' "You Never Give Me Your Money" (specifically, the part where Paul sings "any jobber got the sack").
And here's Oranger, rather obviously acknowledging the source of its borrowed melody by calling their song "Sorry Paul": its verse melody is taken from the "ooh-ooh" section of "Every Night" by Paul McCartney.
And to prove that it's not only McCartney whose tunes are borrowed, here's Mitch Easter stealing the guitar lick from the Guess Who's "No Time" for his "Sights Set on Heaven."
Antecedent to all this (not posted) is of course Neil Young's "Borrowed Tune" - which (Neil explicitly acknowledges, both in the title and in the lyrics) takes its melody from the Rolling Stones' "Lady Jane."
Ashley Park "Town & Country II & III" (Town and Country, 2000)
Oranger "Sorry Paul" (The Quiet Vibration Land, 2000)
Mitch Easter "Sights Set on Heaven" (Dynamico, 2007)