cat http://www.eall.com.br/blog | tee http://www.posixrules.blogspot.com

First of all, the actual implementation of that command, was in the blogger manual pages (http://help.blogger.com/bin/answer.py?answer=47270#feed).
Reading, i could find the following information:

Feed Widget

A feed widget contains, in addition to its own information, a list called feedData, which contains all the items in the feed. Each of those items in turn contains various pieces of information about themselves. When referencing this kind of data, you'll need to loop through each item in the list, with something like . Then use notation such as or to get the information for each item.

Ok, but reading more... gives more:

title: the item title.

summary: A snippet from the item, if available.

So, just a few modifications on the original template, and the result is above...