We're coming to the end of the week so that means it's time to take a look at the world of YouTube again!

This time, we have the science behind weight loss, the Curiosity landing in HD, an incredibly tiny bicycle and Primrose the premature donkey.

Ever wanted to learn about the science behind weight loss? This video does a great job. (35 000 views)

This "honest demo" of an iPhone 5 is pretty hilarious, we have to admit. (1.9 million views)

We all have little games we play, as this video proves. What did you play as a kid? (1.2 million views)

The Curiosity rover landing on Mars is worth a look once more thanks to this new high-resolution clip. (248 000 views)

This guy rides a bicycle – oh yeah, it's about the tiniest bicycle we've ever seen. (295 000 views)

Ever wondered about the origins of Homer's catchphrase? The voice of Bart's dad explains. (201 000 views)

Page two: Primrose the donkey and more!