Knocking sound coming from my engine?

[Anaconda]

http://www.youtube.com/watch?v=hl5byiFCNwk

I took the liberty of recording it on video so you'll get to hear it properly, rather than just describing it.
If you want to skip forward to seconds 25-42, you'll hear a soft knocking noise coming from the engine. I started from a stop sign and rolled on the throttle, did not fully let out the clutch and revved harder. then came a LOUD pop from the engine and then the rpm began to rise. This weird knocking sound is making me a bit concerned so I want to know what your thoughts are. I'm going to bring it to my local shop to have them check it out too.

[tykho]

I hear a soft knock too when idling on my 07 F, and the video sounds about like the same thing, but Suzuki has a service bulletin that states that it will not harm the engine, it's simply cam shaft play. I hear it's somewhat expensive to fix if it isn't under warranty, so I don't think I'm going to bother with it.

http://tinyurl.com/ylalm7l

[Anaconda]

The sad thing is that i didnt have the knocking sound till i messed up that evening.....why did i even bother trying to beat traffic?

Update: well, today when i turned it on, it had some backfire noises and a serious lag in throttle to rev.  I would twist the throttle, but the rpm rises after a 1/4 second delay....not good. I definitely need to take it to the shop