Do commas, periods, and @ signs in link text dilute keyword benefit?

[squared]

Hi all,

I'm just wondering if Google dilutes the value given to anchor text when there are other grammatical characters in the link text. For instance a period, or a comma, or, in my case, an @ sign.

I'm creating a directory and when I link to other pages that aren't within the same category I link like this: keyword@ [webmasterworld.com]. Does the @ sign dilute some of the value of the keyword in the link text? Should I be leaving it out of the link text like DMOZ does? Yahoo does it the way I'm interested in doing it.

Or, am I fussing over something that isn't worth fussing about?

-Squared