well all you need is a broken disk drive. we all know that servos are expensive and hence not affordable to all.
so here i am with a instructable on HOW TO GET A SERVO
Step 1: What All You Have to Do
what all you have to do is just went to a computer shop and ask for broken dvd drives or cd drives.
it will cost about 10 to 30 rs.
now just take the geared part a take it apart using a hand saw.
now you can easily use it in place of servo.
i bring out this servo as few months back i myself was facing a problem as the servo was not available locally and even e bay was not able to provide it.
hope you like it and if you are facing similar problem then you can solve it.