Arancini are said to have originated in Sicily in the 10th century and have since then been a typical Sicilian dish.These are rice balls coated in breadcrumbs and available in a variety of different fillings, e.g. ragu, mozzarella, mushrooms etc. They are called 'arancini' because they are the size of oranges. They make for a nice (and filling) snack. The place is always very busy thought there are no tables and everybody is standing outside with their arancino wrapped in paper. You will be given a fork (for free) if you ask for it. The handy thing is that Mondo Arancina is bteween two of the best gelaterias in Rome, next to them is Gelarmony, that offers delicious ice-'creams' made from yoghurt while also offering a range of soya based ice-creams; while around the corner is the gelateria dei Gracchi. During summer nights all these places are packed, mainly with Italians. As these palces are just 13 minutes walk from Piazza del Popolo it might be worth coming here for a (standing) lunch-break.