You'd be wasting your money as it is one of the exceptions listed a reserved word in the applicant guidebook.

.localdomain would be better.

Also .local

"Despite not being a valid top-level domain in the Internet, considerable DNS traffic that queries the local domain exists in the public Domain Name System.[1] In June 2009, the L root server received more than 400 such queries per second,[2] ranking 4th in DNS traffic of all TLDs after COM, ARPA, and NET." [1]

Scary potential for mischief-making. Hopefully ICANN would reject applications for these domains, but I'm not sure I'd take that level of competence for granted.

[1] http://en.wikipedia.org/wiki/.local

.local is already spelled out as a reserved word in the application guidebook.

.local is the default 'local domain' in most routers, it couldn't be used reliably as a tld. These queries are probably just routed by mistake/buggy software.