Pulling out IS a form of birth control. When done consistently, it is almost as effective as condoms.

Pulling out is the best idea for getting your stupid ass pregnant. I cannot tell you how many friends have had to deal with the consequences of pulling out. And beyond anecdotes, health experts put "pulling out" as only 70% effective -- so have sex once a month like that and chances are you'll conceive within the year. Compare it with the 94% condom rate.

Extuno and Correctinfo, that is just not true. Planned Parenthood says that pulling out is 96% effective if always done correctly, which, as ladynuca says, is almost as effective as condoms (98%). Check it out:

http://www.plannedparenthood.org/health-…

It is a widespread myth that pre-ejaculate contains sperm - I'm sure it's one that is even disseminated (ha ha) in sex-ed classes. However, it has long been scientifically proven that it does not:
http://www.ncbi.nlm.nih.gov/pubmed/12286…

The only way it could is if there is still live sperm left in the urethra from a recent ejaculation which is then carried out by the fluid. But this sperm can be flushed away by urinating after ejaculation, if you plan to continue playing.

Of course it is not recommended for guys dealing with premature ejactulation, or for inexperienced guys who won't have enough awareness and self-control to pull out on time. That's why it has a bad rap in the U.S., because it's a terrible public health idea to recommend it to teenagers, people under the influence of alcohol or drugs, or people having casual sex with people they don't know and trust. But if you're with someone you trust to pull out on time, it's actually a very good method.

Scientifically proven: no sperm in pre-ejaculate:
http://www.ncbi.nlm.nih.gov/pubmed/12286…

Planned Parenthood says: pulling-out 96% effective:
http://www.plannedparenthood.org/health-…

I'm with the lettuce. I looked up the statistics after my friend told me she was using withdrawal only, so I could tell her she was being a fool. I was surprised to find that perfect use is actually pretty effective. The main problem with it is that huge gap between perfect and typical use, which means that most men are crap at getting their dick out in time. It's not a good method for most people, but if the man involved has the necessary self-control, doesn't leave sperm hanging around between rounds, and the couple is willing to deal with a few extra percentage points of risk, it's a reasonable choice for them to make.