Bob Dylan, the metaphysician who diagnosed the subterranean homesick blues, is 70 today. May he stay forever young.
From Don't Look Back (1967), D.A. Pennebaker's documentary attempt to unwrap the enigma inside the riddle of Dylan's troubadour persona, to I'm Not There (2007), Todd Haynes' impressionistic reconstruction of the many lives of Dylan, starring Heath Ledger as the romantic figure, Cate Blanchett as the electric musician and Richard Gere as the outlaw artist, Dylan has denied and defied attempts to simplify him or classify him.
In between these two film landmarks are Sam Peckinpah's  Pat Garrett and Billy the Kid (1973), featuring Dylan as shy outlaw named Alias, Renaldo and Clara (1978), Dylan's broody account of his Rolling Thunder Review, Masked and Anonymous (2003), Larry Charles' bizarro film starring Dylan as a folkie recluse living in Mexico and No Direction Home (2005), Martin Scorsese's elliptical portrait of the enigma.
(For my money Dylan is a more vital presence in Scorsese's The Last Waltz [1976], a concert film of The Band's last show, singing "Baby, Let Me Follow You Down.")
As a rule on screen Dylan flirts with the camera, mostly denies direct eye contact, leaves you wanting more. He'd rather be heard than seen, and that's a good thing.

 Dylan songs permeate the movies. When words fail the characters, he is reliably eloquent. From "Just Like a Woman" in Coming Home and "Tangled Up in Blue" in Truly, Madly, Deeply and from "Blowin' in the Wind" in Forrest Gump to "I Shall Be Released" in Taking Woodstock, his music and lyrics take us places the filmmakers sometimes cannot.

He wrote the evocative "Knockin' on Heaven's Door" for Pat Garrett and the crankily funny "Things Have Changed" for Wonder Boys, songs that deepen these character studies. As to why he and Adam Sandler have never played father and son on screen, I cannot say. But the resemblance is uncanny.
Your favorite Dylan cue in the movies?