I’ve the Kindle 2 and it works well under sunlight. From what I heard, the Sony Reader does not have screen as good as that of the Kindle.

Between the Kindle 2 and Sony Digital Reader, I’ll suggest the Kindle 2 because it has free wireless and text-to-speech function. There are more ebooks you can find available for the Kindle too. There are some good comparison between them here:

http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2Freview%2FR3ULAFVHBGYVQP%3Fie%3DUTF8%26ref%255F%3Dcm%255Fcr%255Frdp%255Fperm&tag=elec-m-20&linkCode=ur2&camp=1789&creative=390957

http://www.speedreaderxreview.com/kindle-2-0-vs-sony-reader-prs-700bc-comparison

And in case you don’t know, Amazon has recently put a price slash on the Kindle 2, and it is now selling $100 cheaper than the price I got my Kindle, and it adds in international wireless access… So take the chance if you want it.

http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2Freview%2FR3KQMNG5BHQFXR%3Fie%3DUTF8%26ref_%3Dcm%255Fcr%255Frdp%255Fperm&tag=elec-m-20&linkCode=ur2&camp=1789&creative=390957

Hope it helps