If you want to see what NLTK can do, but don't want to go thru the effort of installation and learning how to use it, then check out my Python NLTK demos.
It currently demonstrates the following functionality:
- part-of-speech tagging with the default NLTK pos tagger
- chunking and named entity recognition with the default NLTK chunker
- sentiment analysis with a combination of a naive bayes classifier and a maximum entropy classifier, both trained on the movie reviews corpus
If you like it, please share it. If you want to see more, leave a comment below. And if you are interested in a service that could apply these processes to your own data, please fill out this NLTK services survey.
Other Natural Language Processing Demos
Here's a list of similar resources on the web: