An effective task for an OL or LD relationship.

Needed: A candle- not scented or coloured-- (may be put inside a condom)
Some lube may be required.

The sub should measure the inside of her pussy. This could be done by inserting the candle deeply and then making a mark to show how deep it penetrates.
Now cut the candle that lenghth - keeping the wick (piece of string inside the candle) intact.

At an appointed time the Dom contacts the sub....could even arouse her and then has the candle inserted inside her... Be creative here...

Then the sub must 'wear' this for a time --- I found 2 hours to be a good time--- while going about her normal day.
Knowing and feeling the candle inside you and knowing that it is your Dom making you feel the sensations is really a great mind game.

Alternative Leave a piece of the candle on both ends, with the wick cut out only in the middle, makes for great viginal and anal penetration.

Recieving sexy or arousing phone calls, emails, IM's in this time really makes for a really satisfying orgasm in the end