I thought that as long as we're talking about things a JW cannot do is discouraged from participating in, I would repost this old chestnut:
Jehovah's Witnesses tell people that they do not have a lot of regulations; that they simply teach the Bible, and that each person makes up his own mind about what they call "matters of conscience." What they don't tell you is that if you become a Jehovah's Witness you will be considered "spiritually weak" if you do any of the following "matters of conscience":
Celebrate Mother's Day
Celebrate Father's Day
Celebrate Grandparent's Day
Celebrate Birthdays
Celebrate Thanksgiving
Celebrate New Year's Day
Celebrate Christmas
Celebrate Halloween
Celebrate Easter
Celebrate Flag Day
Celebrate Independence Day (Fourth of July)
Celebrate Hanukkah
Celebrate St. Patrick's Day
Celebrate Valentine's Day
Celebrate Any "worldly" Holiday (that's ALL of them)
Sing Traditional Holiday Songs
Join the Boy Scouts
Join the Girl Scouts
Buy Girl Scout Cookies
Become a Cheerleader
Attend class reunions (No "Worldly" association)
Go to the school prom
Play School Sports (No competition allowed)
Play Professional Sports
Join any organization that has ties to "Christendom"
Join any Fraternal of Sororital organization
Shop at the Salvation Army
Volunteer for the Salvation Army
Shop at Church run thrift stores
Shop at Church Garage Sales
Shop at any Store that has Christian ties
Contribute to the Red Cross
Join the YMCA
Join the Military
Become a Police Officer (with any rank above patrolman)
Attend Alcoholics Anonymous
Salute the Flag
Sing the National Anthem
Go to War
Learn karate
Vote
Discuss politics
Run for any Public Office
Campaign for a Candidate
Participate in the affairs of any Union to which you may be a member
Buy lottery tickets
Gamble
Date without supervision - regardless of your age
Watch R rated movies
Cannot work on another Church if it's a regular customer
Own a religious picture or statue
Smoke cigarettes, pipes or a cigars
Sell cigarettes, pipes or a cigars
Accept Blood
Donate Blood
Use the Internet
Wear blue jeans or casual clothes to the Kingdom Hall
Wear pants to the Kingdom Hall if you are a female
Wear skirts or dresses that are above the knee at any time
Wear any type of long hair if you are a man
Wear a beard in some Kingdom Halls
Pierce ears if male, other body parts if female
Get a Tattoo after you become a JW
Say curse words
Toast drinks (pagan origin)
Throw rice at a wedding (pagan origin)
Say "Bless You" when someone sneezes
Say "Good Luck!", "Wish me Luck", "I was Lucky" or "You were Lucky"
Tell ghost stories
Practice Yoga
Own a Smurf
Watch TV shows, "Sabrina, the Teenage Witch", "Touched by an Angel", or "Bewitched"
Say "It was fate" or mention anything to do with "fate"
Engage in any risky acts such as: Sky Diving, Bungee Jumping & Hang Gliding
Have Jesus as your Mediator and Savior
Wear or own a Cross
Attend another Church (Spiritual Fornication)
Associate on a regular basis with nonbelievers
Associate with ex-JWS
Marry a nonbeliever
Marry in another Church or attend a wedding in another Church
Have a funeral in another Church or attend a funeral in another Church
Pray, including holding your head down, when a nonbeliever prays
Read criticism of the Watchtower Society
Question the Watchtower Society on any doctrine, dogma or policy
Exercise your own conscience if it goes against what the Watchtower says
If you are a woman you can't pray in the presence of men, without a covering on your head
To demonstrate that they are "spiritually strong" a member will be expected to:
Attend 5 hours of "meetings" each week
Go out in field service regularly to recruit new members
Report your field service activity to the congregation each month
Attend regular scheduled conventions
Give talks at the congregation (whether young or old, male or female)
Read and fully understand their teachings
Prepare for each meeting
Study with family
Raise their children as JWs
Convert their unbelieving spouse
Fully accept the Watchtower's authority
Follow the Watchtower's teachings about what is acceptable sex for married couples
Dress according to their rules at the Kingdom Halls, Service and conventions (no exceptions): Women and small girls must wear dresses, Men must wear dress pants with dress shirts and ties
Associate only with fellow members
Report on fellow members including your family, if they are caught doing something against Society's rules