While I certainly am not questioning the potential uses of this, it also gives me have horrible flashbacks to the days of using MSN Messenger -- when 75%+ of my contacts felt it necessary to have to at least two smiley faces, three hearts, and a music note on either side of their actual name.

Wow, we launched this like 2 years ago (okay, September 16, 2008 to be exact) at TwitterKeys.com. Was wildly popular for a week or two and then died off.

This is potentially really handy, but it failed my math test:

   ∃ x | x ∈ ℝ

But, then again, it's Twitter, not Mather.

At first, I asked myself "why shouldn't I just use the character map application built into every (windows) pc?", this may be organized, better, so I realized that the real question is "why is this branded as 'twitter' symbols?"

SEO

I miss the recycling symbols: ♺, ♻, ♲, ♼ and ♽ Useful for "classic" retweets.

There are much more typographically useful symbols. I made a Google spreadsheet to keep track of the ones I use:

‘ ’ “ ” — … • ½ ™ Ⅳ and lots of other ones that are much less useful.

Double-clicking the character doesn't always work for me in Opera 10.51 (winXP), but highlighting the character by click-dragging always does.

So that's what they're called.