A couple Japanese questions...

[ZedKnightly]

the level of politeness to use depends on who your talking to.
say your introducing someone to someone at work, or business,
you would most likely use

-kochira wa sato desu (if your introducing sato in person)
-sono kata / sochira wa sato desu (if sata is currently far from you and the one your talking to)

while on normal occasions you can use hito instead of kata, as kata is the polite form of hito. can be used with friends etc

- sono hito wa boku no tomodachi desu! - that person is my friend (when talking to someone you know personally, with a little touch of respect)

while theres also a case like your introducing your close friend to your other close friends like:
-koitsu wa tom desu --> this fellow , guy is tom. (physically introducing someone)
-aitsu wa boku no tomodachi desu - that person is my friend.

of course if you use this on people u are not intimate with youl be the most disrespectful gaijin of the year. ehhe