Specify stopwords for sentence input!
Stopwords are query terms that will be thrown out, ie. the junk or noise words like "a" and "the". If you set good stopwords, your users can search on sentence fragments or even whole sentences, and only the important words will get looked up. For example, "the book" could search for just "book", "What is a carburetor?" could search for just "carburetor", and "Tell me about the history of the presidency" could search for just "history" and "presidency". It's up to you. All of your site's words will still actually be in your index and concordance (text excerpts), because PicoSearch doesn't want to limit you.
You can now set your stopwords in your Account Manager under the Designing features. Stopwords are only a design element because they are a presentation trick and not real natural language parsing, so you shouldn't mislead your visitors into thinking that you really understand what they're saying. But used properly, stopwords can be the cornerstone of a very effective question-answer database, your own FAQ system. Pages can be titled by the question they answer, and the best answer for each user's question can come out on top most of the time. Or you may just wish to use stopwords to clean up your queries and query logs, helping to focus your searches on your critical product terms.
Whatever your use, stopwords are a great new feature, so consider what they might do for you.