I noted a post that said one of the advantages of having a house in Megaton was that you could always get a haircut. Why do I want it?

Roleplaying advantages.

It's for when you're having a mid-character crisis and need to shave your head

It's fun! My character has slowly gone through all the colours of the rainbow on her head. Neon blue does not affect sneak skill.

When my character moved up to large-town evil, rather than small-town evil, he celebrated with a new look.

It would be kind of neat if your hair(and facial hair for the male/hirsute female characters) would actually grow whilst playing and give the haircuts added meaning. I have been playing for several months(in-game) so my hair would be quite long and shaggy by then.

I try to reflect this by getting the survivalist or rough beard look, if I'm going to be out in the wastes for a while.

What happens if your character suffers from Radiation Poisoning? Would you "remove" clumps of his hair?;) LOL!