Found some really cool resources for devleoping applications for these services:

Blogger.com:

http://www.blogger.com/developers/api/1_docs/

Google.com:

http://www.google.com/apis/

Amazon.com:

http://www.amazon.com/gp/browse.html/103-2952669-8856635?%5Fencoding=UTF8&node=3435361

Ebay.com:

http://developer.ebay.com/DevProgram/developer/api.asp

Check it out.