Having lived with my mother my entire childhood (at least the bit of it, where I had left the potty), I never quite got to understand the point of standing up while peeing. As a matter of fact - I found out that due to the structure of the human body, peeing while standing left you with a lot of drops in the underpants - not very sexy. If you've gone to the toilet just a couple of times during a night out and manage to get it on with some chick. I'm a proud I-sit-while-I-urinate kind of person, and I actually trained my father into doing the same (like a dog who's been trained to use a kitty litter box)

I am told that this is typical of men who have a Prince Albert piercing. Not suprsingly, having a heavy metal ring through one's urethra prevents the urine from travelling in a straight and predictable line. It's a bit like putting your thumb over the nozzle of the hose when you're watering plants; the water shoots out faster and goes farther, but sprays all over the place.

Anyhow, to answer your question, the entire point of standing up while peeing is to minimize the time spend in the restroom. Ideally, relieving oneself would be like a NASCAR pit stop. In and out in thirty seconds. Any longer and you run the risk of accidently seeing another man's penis and being accused of being gay. (See Male Bathroom Etiquette and homophobia.)