If you have a 2nd generation Kindle or a DX, there's a software update available at http://www.amazon.com/gp/help/customer/display.html/ref=hp_navbox_top_kindle6i?nodeId=200529740  There are instructions there if you'e never updated your software before. People say it adds another larger font size and seems to speed up the page turns, which I thought were quite fast already. Some people say their display is crisper, too. 

If your software is not 2.5.7, then this will be an update for you. 

They're also saying that Amazon will probably start rolling it out via WhisperNet in a couple of weeks, if you don't want to download it manually. They generally roll out updates in groups over periods of several days to several weeks, depending on how big the update is. 

This is only for the 2nd generation model Kindle and the Kindle DX, not the K1 or the current Kindle. 

thanks- updating it now  :)