I got this list (from Rev Big Jim I think). I can't guarantee it's accuracy but worth checking out...

Oh. and I do know that McCoys, Lowes, and Home Depot give 10% everyday to retired / active duty military.

Diccounts

 RESTAURANTS:

Applebee's:            15% off with Golden Apple Card (60+)

Arby's:                    10% off (55+)
Ben & Jerry's:         10% off (60+)dm

Bennigan's:             Discount varies by location (60+)
Bob's Big Boy:        Discount varies by location (60+)

Boston Market:       10% off (65+)

Burger King:            10% off (60+)
Chick-Fil-A:             10% off or free small drink or coffee (55+)
Chili's:                     10% off (55+)

CiCi's Pizza:            10% off (60+)
Denny's:                  10% off, 20% off for AARP members (55 +)
Dunkin' Donuts:       10% off or free coffee (55+)
Einstein's Bagels:    10% off baker's dozen of bagels (60+)
Fuddrucker's:          10% off any senior platter ( 55+)
Gatti's Pizza:           10% off (60+)

Golden Corral:        10% off (60+)
Hardee's:                $0.33 beverages everyday (65+)
IHOP:                      10% off (55+)

Jack in the Box:       Up to 20% off (55+)
KFC:                        Free small drink with any meal (55+)
Krispy Kreme:         10% off (50+)
Long John Silver's:  Various discounts at locations (55+)
McDonald's:            Discounts on coffee everyday (55+)
Mrs. Fields:             10% off at participating locations (60+)

Shoney's:               10% off
Sonic:                    10% off or free beverage (60+)
Steak 'n Shake:      10% off every Monday & Tuesday (50+)

Subway:                10% off (60+)
Sweet Tomatoes:   10% off (62+)
Taco Bell :              5% off; free beverages for seniors (65+)
TCBY:                   10% off (55+)
Tea Room Cafe:    10% off (50+)
Village Inn:            10% off (60+)
Waffle House:       10% off every Monday (60+)
Wendy's:              10% off (55 +)
Whataburger:        10% off (62+)
White Castle :        10% off (62+)

RETAIL & APPAREL :
Banana Republic:    30% off (50+)
Bealls:                   20% off first Tuesday of each month (50+)
Belk's:                   15% off first Tuesday of every month (55+)
Big Lots:                30% off
Bon-Ton Dept        15 % off on senior discount days (55 +)
C.J. Banks:           10% off every Wednesday (50+)
Clarks :                 10% off (62+)
Dress Barn:           20% off (55+)
Goodwill:              10% off one day a week (date varies by location)
Hallmark:              10% off one day a week (date varies by location)
Kmart:                  40% off (Wednesdays only) (50+)
Kohl's:                  15% off (60+)

Modell's Sporting Goods:  30% off

Rite Aid:               10% off on Tuesdays & 10% off prescriptions
Ross Stores:        10% off every Tuesday (55+)
The Salvation Army Thrift Stores:  Up to 50% off (55+)
Stein Mart:           20% off red dot/clearance items first Monday of every month (55 +)

GROCERY :
Albertson's:                                 10% off first Wednesday of each month (55 +)
American Discount Stores:        10% off every Monday (50 +)
Compare Foods Supermarket:  10% off every Wednesday (60+)
DeCicco Family Markets:            5% off every Wednesday (60+)
Food Lion:                                    60% off every Monday (60+)
Fry's Supermarket:                      Free Fry's VIP Club Membership & 10% off every Monday (55 +)

Great Valu Food Store:              5% off every Tuesday (60+)
Gristedes Supermarket:            10% off every Tuesday (60+)
Harris Teeter:                               5% off every Tuesday (60+)
Hy-Vee:                                       5% off one day a week (date varies by location)
Kroger:                                        10% off (date varies by location)
Morton Williams Supermarket:   5% off every Tuesday (60+)
The Plant Shed:                       10% off every Tuesday (50 +)
Publix:                                        15% off every Wednesday ( 55 +)
Rogers   Markelace:                  5% off every Thursday (60+)
Uncle Guiseppe's Marketplace:  15% off (62+)

TRAVEL :
Airlines:
Alaska Airlines:               50% off (65+)
American Airlines:           Various discounts for 50% off non-peak periods (Tuesdays - Thursdays) (62+) and up (call before booking for discount)
Continental Airlines:        No initiation fee for Continental Presidents Club & special fares for select destinations
Southwest Airlines:          Various discounts for ages 65 and up (call before booking for discount)
United Airlines:                 Various discounts for ages 65 and up (call before booking for discount)
U.S. Airways:                    Various discounts for ages 65 and up (call before booking for discount)

Rail:   Amtrak:                  15% off (62+)
Bus:   Greyhound:           15% off (62+)  Trailways Transportation System: various discounts for ages 50+

Car Rental :
Alamo Car Rental:           Up to 25% off for AARP members
Avis:                                 Up to 25% off for AARP members
Budget Rental Cars:       40% off; up to 50% off for AARP membe rs (50+)
Dollar Rent-A-Car:         10% off (50+)

Enterprise Rent-A-Car:  5% off for AARP members

Hertz:                              Up to 25% off for AARP members
National Rent-A-Car:      Up to 30% off for AARP members

Overnight Accommodations:
Holiday Inn:                     20-40% off depending on location (62+)
Best Western:                40% off (55+)
Cambria Suites:            20%-30% off (60+)
Waldorf Astoria - NYC: $5,000 off nightly rate for Presidential Suite (55 +)
Clarion Motels:              20%-30% off (60+)
Comfort Inn:                   20%-30% off (60+)
Comfort Suites:             20%-30% off (60+)
Econo Lodge:               40% off (60+)
Hampton Inns & Suites: 40% off when booked 72 hours in advance
Hyatt Hotels:                  25%-50% off (62+)
InterContinental Hotels Group:  Various discounts at all hotels (65+)
Mainstay Suites:          10% off with Mature Traveler's Discount (50+); 20%-30% off (60+)
Marriott Hotels:             25% off (62+)
Motel 6:                         Stay Free Sunday nights (60+)
Myrtle Beach Resort:   30% off (55 +)
Quality Inn:                    40%-50% off (60+)
Rodeway Inn:                20%-30% off (60+)
Sleep Inn:                      40% off (60+)

ACTIVITIES & ENTERTAINMENT :
AMC Theaters:                          Up to 30% off (55 +)
Bally Total Fitness:                    $100 off memberships (62+)
Busch Gardens Tampa, FL:     $13 off one-day tickets (50 +)
Carmike Cinemas:                    35% off (65+)
Cinemark/Century Theaters:    Up to 35% off
Massage Envy - NYC:               20% off all "Happy Endings" (62 +)
U.S. National Parks:                  $10 lifetime pass; 50% off additional services including camping (62+)
Regal Cinemas:                         50% off Ripley's Believe it or Not: @ off one-day ticket (55 +)
SeaWorld, Orlando , FL :          $3 off one-day tickets (50 +)

CELL PHONE DISCOUNTS :
AT&T:                          Special Senior Nation 200 Plan $19.99/month (65+)
Jitterbug:                     $10/month cell phone service (50 +)
Verizon Wireless:       Verizon Nationwide 65 Plus Plan $29.99/month (65+).

MISCELLANEOUS:
Great Clips:      $8 off hair cuts (60+)
Supercuts:        $8 off haircuts (60+)