nano projectors?

[Haopengyou]

I have seen projectors being sold for about $200 but I have yet to read a review that compares them to the standard "big, bulky and expensive" projectors. They are described as nano projectors or pico or some such. Can someone help me compare the two technologies so that I can make an intelligent purchasing decision? The pico are tempting, certainly because of their price but also because the "bulbs" are rated to last 10,000+ hours.

[jagabo]

Low resolution, low light output, low contrast ratio. For example:

http://www.newegg.com/Product/Product.aspx?Item=N82E16824219063

Native Resolution VGA: (480x320)
Brightness: 11 lumens (bright mode)
Contrast ratio: 1000:1

Compared to, say:

http://www.newegg.com/Product/Product.aspx?Item=N82E16824219072

Native Resolution: 1024 x 768
Brightness: 2500 ANSI Lumens
Contrast Ratio: 2500:1

Or:

http://www.newegg.com/Product/Product.aspx?Item=N82E16824157082

Native Resolution: 1920 x 1080
Brightness: 1800 lumens
Contrast Ratio: 36000:1