[libria]

Well there aren't many convenient choices on a phone. # is used in twitter, * is often used by the carrier. Might have been better to prefix with just "z".

[scoot]

Twitter existed before the hash-tag - that was a user created meme: http://support.twitter.com/articles/49309-what-are-hashtags-...

[treetrouble]

disabling the use of #get as a hashtag is still better than disabling its use as an english word