You must take a walk in the woods completely naked

streak
 

you must streak in your local park and must be naked at least 15 mins

Do 25 star jumps in your front garden naked.

do some nude sunbathing while it is quite cold :) for 15 mins

Dance the Macarena
http://www.youtube.com/watch?v=vlzwuFkn88U (if you don't know it)
Naked in front of a window for 10 mins. Music is optional.

clean your house fully naked

You have to go naked to the toilet and leave your clothes outside the door for 5 days. Redress when you finished

spend a day naked. My limit is very public dares

Mow the grass naked

run up and down your street naked. the time of day is up to you.

Stand naked in your front yard for 2 minutes with your eyes closed. This way, you won't know if anybody sees you.

For mine, please make it involve humiliation and/or light public.

In the night, so it's too dark to find it easily, throw a small object (must be no larger than a house key - make it the key if you dare :P) out into the front garden with your eyes closed so you don't see where it landed. Then go outside naked, and you cannot come back in or put clothes on until you've found the object in the dark.

You must exercise completely naked near an open window. Must exercise for at least 2 hours

Touch your toes 20 times while keeping a pen in your butt

Do your laundry, wash everything so you must remain fully naked until finished.