tilde, a.k.a. the scribbly line, at, around, approximately, or
In online usage, this scribbly horizontal line used to signify an individual user's Web site that is housed on the server of an ISP, but it has largely been replace with /user/ folder. For example, it used to say http://www.well.com/~silly but now it says http://www.well.com/user/silly
The tilde also means "at" or "around" or "approximately" as in "Let's meet in front of the restaurant ~7pm." You will also see it used in smileys ;-)~
In symbolic language, it also means "or" whereas the = sign means "and" for example, "[[2B~not2B]]" = "To be or not to be."