Public Speaking without slides?

As a Computer Scientist, it is only natural for me to rely heavily on my computer skills to enhance my presentation, today I plug my remote HDD into office's 5 years old Dell, it was complaining about the remote HDD has overshoot the USB's power supply (something like that). So... I was done with no presentation slides and had to rely completely on my ad-hoc speaking skills.

Surprisingly I have done quite well, and I am even more happy that I have more jokes coming out spontaneously as I go on.

Emm... thats a breakthrough for me. I like it. If you were there, drop me a line to criticise.

Thank you~