This site is so cool! Not only can you make a "wish list" for the books that you want to read, but you can also see what all your friends are reading too. This site has really helped my not buy books that I want to read in the future. Instead I just add them on to my "to read" shelf and they are saved forever. I love getting email updates of what my other friends are reading too.
Recently my friend Allison posted a list on her blog of all the books she read in the last year. I can't remember all the books I read last year so I just went on Good Reads and sorted my "read" shelf by date.