Making a Difference

In the first week of school this year I received an email from a teacher who was a little frazzled because her classroom Interactive White Board (IWB) was not displaying the computer input correctly.  I had a free moment before leaving to go to a workshop so I called over to the school to speak with the teacher.
When I got the teacher on the phone they proceeded to describe to me what the problem was and I immediately realized what was going on and that it was a simple fix.  Now there was a problem that came up, I would not be able to get to their school until the next day so I decided to walk the teacher through the fix over the phone while she was in her classroom.
I had the teacher go through the steps slowly with me by describing the steps they would need to do to fix the problem with the IWB.  The teacher listened to me and was able to do the steps to fix the problem and even talked the steps back to me and said that they would be able to fix the teachers IWB in the room next door because they had the same problem.
She was very excited to have things working and her students, that were in the classroom and behaving incredibly well, were excited as well.  She had the students thank me over the phone which made me feel very good.  Now what was even better was the fact that two days later an inter-office envelope came into me with the following card that the students in her class made for me to thank me for taking the time to call their teacher to help her with the problem.

To me I was just doing my job but to the students I made a difference by taking the time to contact the teacher and help her out over the phone.  I had a friend some number of years ago tell me to figure out how you can make a difference and take it as far as it will go.
So now I have to ask you.. How have you made a difference today?