Fa la la to you, too.

HANG
Now You Know
What: Man-about-downtown Tony Arcabascio tells you how to torch a car, avoid assault charges, walk someone through a trip, make the girls love you, etc.
Why: For a “hot book, hot drink, and hot smoke.”
When: Fri., 5-8 p.m.
Where: Anything, 51 Hester St., at Essex St. (212-777-0919).

HEAR
Unsilent Night
What: Bring a boom box, pick up a tape, and join in a parade of holiday music.
Why: Do you hear what we hear?
When: Sat., 6:45 p.m.-8 p.m.
Where: Meet at the arch in Washington Square Park. Parade ends in Tompkins Square Park. For more info, e-mail boombox@mindspring.com.

SEE
A Very Merry Unauthorized Children’s Scientology Pageant
What: Les Freres Corbusier’s jubilant cast of children play Tom Cruise, John Travolta, L. Ron Hubbard, and more.
Why: Cross your fingers for a guest appearance by baby Suri.
When: Thurs., 7 p.m.; Fri. & Sat., 7 & 9 p.m.; Sun., 3 p.m.
Where: 4th Street Theatre, 83 E. 4th St., b/t Bowery & Second Ave. (212-239-6200). Tickets online at telecharge.com.

DO
Operation Santa Claus
What: Play bowl full of jelly for a child in need by picking up a Dear Santa letter at the post office.
Why: Seems like the write thing to do.
When: Thru Dec. 23. Mon.-Wed. & Fri., 9 a.m.-4:30 p.m.; Thurs., 9 a.m.-7 p.m.; Sat., 9 a.m.-4 p.m.
Where: James A. Farley Building, 421 Eighth Ave., at 33rd St. For more info, call the Santa hotline at 212-330-3000.

BUY
Hollywould Insane Sale
What: Up to eighty percent off clothing, shoes, and handbags. Plus the famed $25 and $50 bins.
Why: The elves have worked hard to cobble those heels. Don’t let them down.
When: Thurs.-Sat., 11:30 a.m.-7 p.m.
Where: 198 Elizabeth St., b/t Prince & Spring Sts. (212-219-1905).

The Gift on Grand
What: Better-than-crafty handmade goods from Deadly Squire, Lena Corwin, Plunket & Pivet, and more.
Why: Gimmegimmegimme. And a happy new year.
When: Sat., 11 a.m.-8 p.m.
Where: 33 Grand St., b/t Kent & Wythe Aves., Williamsburg.