Emojis are only a fingertip away on your iPhone... it was only a matter of time until they show up on OSM as well. The following query finds all those emojis - worldwide: http://overpass-turbo.eu/s/l6r
Thanks to tyr_asd for the MapCSS enhanced version below
A bit more serious: how about searching for mixed language names like
name=Vinh-Loi Asien-Supermarkt 榮利市場 : check out the following query! http://overpass-turbo.eu/s/l6s
Do you find regular expressions with full Unicode support useful and want to see them in one of the next official Overpass API releases? It's your turn now, vote for it on Github or leave a comment here!