Pull up the tone volume?

Hi.. Could anyone give me an idea about how to amplify the tone volume?

I'm runnning my atmega328 at 3v and the buzzer is 5v. so the volume is running low.

A transistor? any idea?

Tks a lot

See this video

https://www.youtube.com/watch?v=cEz1i5xzGEE#t=100

Thank you.. Thats what I was looking for.

Tks a lot!