I recently had to teach a lesson on inventions in Life Elementary Textbook (10C Why Haven't Scientists Invented it Yet p. 122-123)

In order to supplement that lesson, I found these online resources helpful:

From the British Council: Inventions

From ESL Conversation Questions: Inventions

I adjusted both of these slightly.
For the British Council Inventions, I put the names of the inventions on cards, so the students could re-arrange the cards on their desks as they debated the order of the inventions.  I also created a slideshow to supplement the lesson.
Cards (docs, pub)
Slideshow (slides, pub).
Questions (docs, pub)
Lesson Plan (drive, docs, pub)




For the ESL Conversation Questions, I copied them onto a separate document, deleted any questions I thought were unsuitable for elementary students, and enlarged the font.  In my class I posted these questions around the room, and had the students walk around the room with a partner to discuss the questions one by one.
ESL Conversation Questions document (docs, pub)

(I'm linking to these materials on this blog so I can find them again when I need them.  I'm also indexing them over here, and here.)

The Internet	light bulb
telephone	refrigerator
braille	thermometer
microscope	printing
paper	the wheel

http://iteslj.org/questions/inventions.html

What are the best and the most useful inventions of the mankind in the 20th and 21st centuries?

What famous inventors do you know? What were their inventions?

How did the invention of television change people's life? Do you think it is a useful invention? What is the role of television in your life? How often do you watch it?

When did you buy or get your first mobile phone? Do you think you can live without your mobile or is it now an important part of your daily life?

Do you use the Internet? What Internet services do you use? Do you feel any addiction to the Internet? How much do you spend on the Internet a month?

What do you think is the worst invention of the mankind? (weapon, atomic energy, cigarettes, television, mobile phones, cars, genetically modified products etc)

Can you name some inventions are you looking forward to? (human cloning, time traveling, eternal-life-pill, AIDS\cancer vaccine, teleportation)

Do you think time machine will ever be invented? Would you like to do some time traveling? What time would you like to visit, what event would you like to witness?

Do you think aging is the problem the mankind can not fight? What discoveries and inventions has been made recently to fight aging?

What is the use of space exploration? What technologies has space exploration brought to our daily life? Do you believe that one day people will live on the moon and on other planets?

What would you invent if you were a scientist?