what does # mean in a text?

[Eddie Castelin]

[No Name]

number.....as in phone number

[Lalala]

Hashtag like on twitter

[Hilbert]

Number

or it's a metadata hashtag
http://en.wikipedia.org/wiki/Hashtag

or it's someone who uses too much twitter pretending to use a metadata hashtag

[Osiris]

I could mean a number of things such as
• number
• hashtag (a way to tag things to a subject)
It depends on the content around it