You often encounter mention of a book on a web page or a blogpost. Sometimes you are intrigued enough to buy (or perhaps download a sample chapter of) the book. You probably end up doing these actions.
Highlight the name of the book and copy it.
Open Amazon.com website.
Select the Kindle book from the search field options.
Paste the book that you copied earlier and run the search.
I find this a bit tedious. So I made a bookmarklet (by made I mean, I found a bookmarklet on the net that was doing some other search and I changed the code a bit to search the Kindle store)
If you want to install this bookmarklet in your browser, head on to http://bit.ly/kindlesearch