buıdʎʇ uʍop ǝpısdn -- (upside down typing)

This is a pretty fun thing to do while chatting to friends, although after awhile it does get annoying, so use this rationally.  Typing upside down usually amazes people because they have never heard of doing this, and most people love new stuff.  To type upside down just go to either here or here.  The second of the two is more simple, but both work depending on how much you care about website appearances.  Its pretty cool and you should check it out.

-- CK