the complete novelty of standing up in the cot will pass, but it is something they will do when they don't want to go to bed...... but for the novelty phase, i just tried to show her i wanted her to lie down then left her to her own devices....

once they are a bit older and standing in the cot i would just say "night night" and try to ignore the fact that she was standing when i wanted her sleeping..... it can become a game to keep lie-ing them down over and over..... you have just got to kind of do the best you can do and rest assured the phase will pass in a fairly short amount of time, then it will be on to something else to drive you nutty!