Update 6/12: Played around with popfly a bit more and learnt quite a few things, which you might want to know:
- There is no way to pass querystring parameters to a mashup currently, this means that the mashup cannot be dynamic w.o. requiring user input: this will be implemented in next release.
- Some blocks like Carousel and Photo Sphere have rendering issues in fx and don't display at all on that browser: again something which will be fixed in next release
Here's the link to the mashup.