Theme: 'Ello...and a, e, i, and u - The letter "L" followed by a long vowel (phonetically), progressing from "A" to "U".
17A. "I'm all ears!" : "LAY IT ON ME!"
25A. "The Six Million Dollar Man" actor : LEE MAJORS. Old TV show.
39A. Polygraph procedure : LIE DETECTOR TEST. Grid spanner.
51A. Like cheaply made movies : LOW BUDGET
64A. Babe Ruth teammate : LOU GEHRIG
Argyle and Jeff here, again. Jeff is the clever one on this Monday. Vowel progression, alliterations, a little misdirection, and clecho's all over the place.
1. Peninsula bordering Southern California : BAJA
5. Triple play trio : OUTS. Rare.
9. In __: right away : A JIFF
14. "'Tis a sad day" : ALAS
15. Shot up : GREW
16. "Git along" little critter : DOGIE. Roy explains it all in this video.(1:51)
19. Soothing cream : SALVE
20. Contemplative direction to turn one's thoughts : INWARD
21. Samsung Galaxy, e.g.: Abbr. : PDA. (personal digital assistant)
23. Christmas song : NOEL. Like Up On the House Top.(1:38)
24. Back in the day : AGO
27. "Horsefeathers!" : "BALONEY!"
30. Questionnaire datum : AGE
31. Question : ASK
32. Carpeting calculation : AREA
35. Based on __ story : A TRUE
43. Fathers, to tots : DADAs
44. Japanese noodle : SOBA. (buckwheat)
45. Fourposter, e.g. : BED
46. NBA's __ Ming : YAO. On July 20, 2011, Yao announced he was retiring from the NBA (Sorry for the typo earlier). His left foot turned out to be his Achilles' heel.
48. Pros with bows : ARCHERS
56. Olive of comics : OYL
57. Mideast bigwig : EMIR
58. Lightly apply : DAB
59. Pierce with an arrow : IMPALE.
62. Military trainee : CADET
66. Leading in the game : AHEAD
67. Drawn-out : LONG
68. Austen title character : EMMA. Film, television and stage adaptations. Wikipedia.
69. Captain, colonel, etc. : RANKS
70. No great shakes : OKAY
71. Big Apple enforcement org. : NY PD
1. "__ Ha'i": "South Pacific" song : BALI. The musical premiered in 1949.
2. Rickman of Harry Potter films : ALAN. That is Professor Snape, as Harry was often reminded.
3. Ignored the light : JAYWALKED
4. Crumbly Italian cheese : ASIAGO. The only "official" Asiago is produced in the alpine area of the town of Asiago, province of Vicenza, in the Veneto region. Map.
5. Psalm words : O, GOD
6. Coffee dispenser : URN
7. Site of Arizona State's main campus : TEMPE
8. Stockholm native : SWEDE
9. Sponsor's spots : ADs
10. "I Love Rock 'n Roll" rocker : JOAN JETT. Clip.(2:57)
11. Arctic abode : IGLOO
12. Half a sawbuck : FIVER
13. Senses with one's hands : FEELS
18. 1982 film set in cyberspace : "TRON". The sequel was "Tron: Legacy" (2010)
22. GP's gp. : AMA. A little extra abbreviation, for effect.
25. Harplike instruments : LYREs. "L" with a long "Y"?
26. Gelling agent : AGAR
27. Hairless : BALD
28. India's continent : ASIA
29. Break bread : EAT
33. Conservation prefix : ECO
34. Awaiting a pitch : AT BAT
36. Insurgent military group : REBEL ARMY
37. One enjoying Wi-Fi : USER
38. SFO postings : ETD's
40. Crack of dawn : DAYBREAK
41. Genesis twin : ESAU
42. Rower's tool : OAR
47. Quirky : ODD
49. Put in an appearance : COME
50. Wi-Fi connection? : HYPHEN. Sure.
51. Aptly named Renault : LE CAR. French.
52. Cornhusker State city : OMAHA. Say hey, Husker.
53. Make broader, as a highway : WIDEN
54. Either California winery brother : GALLO. Ernest or Julio.
55. Purchase for a Kindle : E-BOOK
59. Pop of pop music : IGGY
60. Wilted : LIMP
61. "My word!" : "EGAD!"
63. NFL successes : TD's. (touchdown)
65. A, in Argentina : UNA.(feminine)