The talk went really well, with positive feedbacks from lots of people. The only problem is that I spent too much time (10 minutes) introducing the problem and had only 3 minutes to do the demonstration. Should have done the reharsal
The slides is available at http://www.slideshare.net/miyagawa/webscraper
I realize that the code snippet is displayed in funny fonts because I use Consolas with my powerpoint. Trying to reupload the file with Courier New. UPDATE: Now re-uploaded!