Refefrence: http://answers.yahoo.com/question/index?qid=20100607151104AAtQxhc

~ “tilde” or “tweedle” or “squiggly line”. Also used as a “swung dash” and in mathematics with other signs to mean “approximately” and in logic sometimes used to mean “not”. See http://en.wikipedia.org/wiki/Tilde,

` “grave accent” or “stress mark”. See http://en.wikipedia.org/wiki/Grave_accen… .

! “exclamation point” or “exclamation mark'. Used to end an emphatic sentence. Also often used in computer languages to mean “not” and in mathematics to indicate “factorial'. See http://en.wikipedia.org/wiki/Exclamation… .

@ “at sign” or “commercial at sign”. See http://en.wikipedia.org/wiki/At_sign .

# “number sign” or “pound sign' or “octothorpe” or “hash mark”

$ “dollar sign”, for example $29.00 would be read as “twenty-nine dollars'

% “percent sign”, so 50% is “fifty per cent''

^ “caret” or “up-arrow head” or “circumflex accent”. Often used on computers to indicate the following symbol(s) would be superscripted in normal typography, that is 5^23 is the same as 5²³. Sometimes called a “carrot” by the illiterate.

& “and sign” or “ampersand”. An abbreviation symbol for “and”.

* “asterisk” or “star”

( “opening parenthesis”

) “closing parenthesis”

_ “low line”, “underbar”, “underline”, “underscore”

- “hyphen-minus”, “hyphen”, “minus”: a typewriter symbol used for both hyphen and minus. Sometimes, when spaces appear on both sides of it, it represents a dash, but a dash is more often built from two hyphen-minuses. In normal typography for dashes there is an en-dash (–) and an em-dash (—) which are different characters.

+ "plus sign”

= “equal sign”

| “vertical line”, “vertical bar”, “pipe”

\ “backslash”

< “less than sign”

> “greater than sign”

, “comma”

. “period”, “full stop”, “decimal point”

? “question mark”

/ “slash”, “virgule”, also usually used on computers as a “division slash” or “solidus”, though in normal typography the division slash is more slanted. Misnamed “SOLIDUS” by Unicode.

" “quotation marks” or “straight quotation marks” or “typewriter quotation marks. Originally a typewriter substitute for “ (opening quotation marks), ” (closing quotation marks), ʺ (double prime used to mean “inches” and “seconds”), and〃(ditto mark).

' “apostrophe'' or “single quotation mark” or “straight apostrophe” or “typewriter apostrophe” or “straight single quotation mark” or “typewriter single quotation mark”. Originally a typewriter substitute for ‘ (opening single quotation mark), ’ (closing single quotation mark or apostrophe), ′ (single prime used to mean “feet” in measurement and to mean “minutes”)

: “colon”, a punctuation mark

; “semi-colon”, a punctuation mark

I started out making links, but Yahoo Answers only allows ten so I did not continue. But if you search on most of my meanings you will find articles that tell you more.

Many of these symbols also have other names in various special disciplines and some even have other common names.