Turns munged text email addresses into clickable links. Even recognizes many anti-spam conventions, such as:

some-address (AT) domain (DOT) com
spam-free -at- email -dot- co.uk
me at myfullname dot name

Should work on nearly every form of email address, even those with unusual special characters and just about any top-level domain.

Updates

UPDATE (3/6/2008):
Some false positive bugfixes: now requires a word boundary at the end of the match string, to prevent thinking the first two letters of a word is a TLD; the plain words at and dot (with no surrounding parentheticals) now require at least one space before and after the word while the symbols @ and . cannot have spaces.

As an example, the above changes will now ignore the following such situations:

Best.Signature.Ever.

The above is a very common phrase in forums. It used to catch this using the Ev as the TLD.

Meet me @ eleven-thirty. Do you understand?
some-fool @ nowhere . com

The above will not be recognized as email addresses, because spaces between the normal symbols are not interpreted. (@) will work, however.

mynameatsomedomaindotcom

The above is no longer treated as an email address. If you know of any forums that happen to use this kind of style, please let me know.

You are encouraged to post a comment if you find any other conventions that this script may have missed, or if you are seeing false positives on pages not containing email addresses. Please post the full url of the page in error.