Have you noticed how many social networiking sites are out there? They can be sort of general based with an emphasis on music and movies like Myspace. Or you can write down what you’re doing throught your day on twitter. You can connect with like mined professionals on linked, but there are also more specific websites.
Some I found today are for booklovers and bookswapping. Yes, really. Here are some links. I probably havene’t found them all.
http://www.paperbackswap.com/index.php
http://www.readitswapit.co.uk/TheLibrary.aspx
This is a rental library
Connects book lovers
http://www.connectviabooks.com/
I did find some others, but they didn’t have a google page rank meaning they were new. I didn’t feel comfortable posting those in case they have some big problems down the line.