] In my mind, the single largest technical issue with
] SiteFinder was that of the assumption that the WWW is the
] Internet - i.e., that a wildcard for Web users wouldn't
] affect other services. This, obviously, is not the case -
] A resource records are protocol-agnostic, as we all know.
] However, there is a rough equivalent to A RRs which are
] protocol-specific: SRV records.

(I think Tom blogged this but I lost it)

Looks like someone beat me to it. I wonder if he has code, though :P

Read on down the thread; sounds like

_http._tcp.*.com IN SRV ...

is not kosher ... but at the same time breaks much less than

*.com IN A ...