Originally Posted by jasem200
is iLiad has feature to search inside books for a word
The iLiad MobiPocket Reader will search for words (definitions) in an open MOBI dictionary, and will lookup a word in a MOBI dictionary when you are reading an e-book, but you can't search for a word in an e-book (as you can with the Windows MobiPocket Reader for example). FBReader will search for a word in the currently open e-book. The PDF reader does not support search, although this might be available at some point since similar PDF readers (on other devices) can do so.
The Kindle has the advantage of supporting essentially only one format (AZW/MOBI), but it is the only E-Ink based reader that does a device-wide search of all documents. This is fast, because each new document is indexed when first installed on the device.