Under Windows, you can do this:
(defun :go (&optional (thing *))
"View THING with some appropriate viewer."
#+:WIN32 (sb-ext:run-program "cmd" (list "/c" "start" (princ-to-string thing)) :search t)
I also started to experiment with (:mail) via mailto:// but that requires url-encoding of the body text and I'm not sure yet how much stuff I'm willing to pull into my minimal environment.
How about (:tweet) for twitter?
(:cut) to copy to the clipboard?
Perhaps we could start to define a "standard" set that's somehow installable via Quicklisp?
Lot's of possibilities!