Best approach for hosting a Chatbot on Twitter?

I have been using the Twitter API to host a basic chatbot, using Python w/libraries (nltk.chat for basic scripted chat and Tweepy for Twitter). Right now I’m using an intermittent polling approach to respond to new direct messages every 30 mins or so. This is because Twitter doesn’t appear to support streams for Direct Messages, and they rate limit API calls. Does anybody else know a better way? Alternatively, are there better platforms for chattin’ that I should be looking into?