Ronen Narkis, JavaEdge 2007: Java on Steroids - Adding Ruby, Groovy and Friends (pdf)
Ophir Radnitz, JavaEdge 2009: Introduction to Scala (pdf)
Itay Maman:

• The Eiffel way of coping with the "null pointer" problem (ppt)
• An informal account of the history of programming languages (pdf)
  

Adi Baron: JBUG 11 - Scala For Java Programmers (slideshare)
Yardena Meymann: Scala at HUJI PL Seminar 2008 (slideshare)
Dror Bereznitsky, Fred Simon, Steve Colebourne: Fantom on the JVM Devoxx BOF (slideshare)
Haim Michael courses collection: http://www.abelski.com/moodle/

...