Considering a typical posting on perlmonks is a mix of HTML, Perl code, jargon not found in typical wordlist used with spell checkers, and the odd URL, I'd say a spell checker could be tons of fun. Specially if you make its auto-correcting feature mandatory. I mean, if Microsoft can do an excellent job with Word (I never see any spelling mistakes in those documents, do you?), we can do too! Let's implement it today!