Tweeting shorthands

As Twitter keeps message posting limited to 140-character long, sometimes it would be better using certain symbols in character set instead of multiple/repeated characters to save message length.

Try this	To/For
… — ‼	Instead of repeating those characters.
« »	Double less/greater signs, or denote arrows: <- ->
‖	"RT @... original message. ‖ your additional comment"  (idea from '// comment' in C++)
≠ ≤ ≥ ±	<>, <=, >=, +/-
⅛ ¼ ⅜ ½ ⅝ ¾ ⅞	Instead of x/y
© ® ™	Instead of (C), (R), TM
α β	Instead of 'alpha', 'beta'

Also these symbols are nice for use:

• ≈ ≡ × ÷
• ∞ ∫ ∑ √ ∂ ∆
• ¬(not) °(degree) ²(square) ³(cube)