*123# como puedo leer esto?
como se dice # ? como se puede leer esto? *123# - estrella ,uno,dos,tres, ... ?
5 Answers
"La almohadilla" "el numeral" "el signo de número" "el cardinal". Todos se usan para decir #
Don't forget 'gato'!

Less formally, I have seen it used as "hashtag". Probably not an accepted use, but as a convenience in forums, etc.
Has anyone made a flashcard set with the computer symbols and Spanish names for them? That would be helpful.... actually any set with computer lingo would be helpful. If you read this and you have made one or know of one, will you PM the link to me?
En twitter en español se dice hashtag como en inglés. A continuación un glosario de términos de twitter en español.