That wasn't bad at all. That was very good, but the thing you need to work on is taking small, unnoticeable breaths in between so that you don't make it obvious. Other than that, great job.
That's pretty good, as Hahanerd said you need to make it less noticable when you breath in, a good way to do it is making a snare drum noise as you breath. I won the talent show back when I was in highschool 4 years in a row because of my beatboxing, now that I am in college I do it just for fun.
Personally i love beardyman as a beatboxer. Not only does he make some remarkable noises but he also rolls it up in a kinda comedy way, and he does like hour long shows, not many people can hold it down for that long and still keep it enjoyable. Here he is anyway http://www.youtube.com/watch?v=qciVXUHTN10
http://www.youtube.com/watch?v=qBdLDARvPmM http://www.youtube.com/watch?v=qBdLDARvPmM http://www.youtube.com/watch?v=qBdLDARvPmM http://www.youtube.com/watch?v=qBdLDARvPmM http://www.youtube.com/watch?v=qBdLDARvPmM http://www.youtube.com/watch?v=qBdLDARvPmM