To provide a good ( but a very short) rest during the class, or even while reading lecture, or during any common communication different variants could be recommended. Some lectures prefer telling some short funny story or jokes. Personally i , never escape the opportunity to give convincing examples of differences of culture ( English and Russian ones). The difference in idioms, (could provide one good example), so, why students who don't know some specific English idiom would never be able to understand it. Or even some practical situations. Try to ask: How many flowers would you present to your mother-in-law? the even or uneven number? In different cultures that is absolutely different and very important!

I would suggest that you read those articles:

• EXPRESS: EXPressing REstful Semantic Web Services
• A Methodology for the Development of RESTful Semantic Web Services for Gene Expression Analysis.