(IMP: Please try this first on some ink stain on waste cloth before working on your clothes.)
1. Spray the hair spray or rub bottled alcohol generously onto the stained area making sure it penetrates the fabric. (You may also soak the area in alcohol for some time to get off the ink stain). Let it sit for some time
2.Scrub it gently & then wash it straight away in the washing machine; the ink should be removed when the washing cycle is done.
NOTE: For leather clothes, try applying a liberal dose of petroleum jelly to the ink stain. Leave the jelly sitting on the stain for several days and then wipe the area clean.
(Info at http://cleaning.lifetips.com)
"So next time your pen leaks in your shirt pocket, don't bin the shirt, just use hairspray to remove it. It doesn't even matter if the ink has dried. You can use the cheapest of cheap hairsprays too as they work better."
By Adam Pash at lifehacker.com
Tip: If you use hairspray, buy the cheapest off brand you can find. They usually have a higher alcohol content & thus more affective.
To Remove Hair Spray/lipstick or gravy stains on clothes:
Just apply any stain remover like "Shout" or "Resolve" & then rub it with strong liquid detergent & water. Scrub lightly & then hand wash first with hot water & later put in washing machine with detergent & all-fabric bleach to remove the dye in the stain. (Info at about.com)