The dollar sign ($) is sometimes used to indicate a hexadecimal number. For example, $3E0 is the hex number 3E0. In the Unix world, all Unix shells support the use of the $ as a prefix to the name of a shell variable or an environment variable.
The dot-com bubble was in large part due to a bunch of callow young men with dollar signs for eyeballs, whose greed and naivete effectively created and destroyed an entire industry in the span of less than five years.
It may mean the end of invisibility as we knew it; with the latest market research estimating buying power among gay and lesbian consumers in the $350 billion-$450 billion range, corporate executives are seeing dollar signs where they once saw controversy and chaos.