Well I've just gone through the search so I might as well post it here.
In essence you have:
- feedjit, my favourite one, I use on my Compastic! blog, check it to see what it looks like. For blogger do not use the Add a Gadget one, I don't quite know what it is supposed to display but it is totally irrelevant. In fact installing is incredibly simple, just go to the website, register and it will take you to your blog for installation.