excerpt plugin or widget??

Is there such a thing as a widget or plugin that would allow me to write my own exerpt for an article?? What I’m hoping for is a plugin or widget that would allow me to write a sentence or two of descriptoiive material that would show up in a google/yahoo/bling search. As it is now, I’ve noticed the article title and first few words show up in a search, which isn’t always descriptive enough.
I’m using WordPress 3.3.1 and at the moment and have the Twenty-Eleven theme although I could change this if needed. My blog is https://blog.mommawolfzpack.com