Hey Debbie....On days that you really want some good practice time, play with an mp3 player on. I use an Ipod shuffle, which is small and clips to your shirt. It doesn't seem to get in the way for me (I run the cords behind my head), and it really cuts down on people coming up to talk to you. If people do come talk to you still, make a big deal about cutting off your music, tell them "sorry I am practicing and listening to my music, I didn't hear you". If they have good advice, you can always take the ipod off and use the opportunity to get the free lessons. If they are just hitting on you, make sure to leave your music on if they try to talk to you again and just shake your head and point to your earplugs (meaning...sorry I can't hear you and I'm not turning off my music for you, so please leave me alone). Good luck with your drills!!
While wearing an ipod can help, it doesn't always deter. Check out one of my practice sessions for grins:

http://pooljourney.blogspot.com/2009/11/earbuds-are-broken.html