Find a Twitter user's recent tweets, or find friends shared by two users.
An exercise using Perl, Dancer, Redis, and the Twitter API.
Check it out at http://twirl-lbrs.rhcloud.com/.
Both Redis (on RedisToGo) and Twitter are subject to rate limiting. If you receive a "Woops..." error, rate limiting is the most likely cause. The application log can be used to confirm that.
(This could be handled by retrying the API call, but this is a demo app written very quickly...)