Welcome Ted to the wonderful world of OS X :). Here's a few quick tips..
- I found X shipped with Panther (IIRC it was an optional install in some subdirectory on the CD)
- my favourite IRC client is X-ChatAqua
- for terminal stuff iTerm
rocks. Classic 3 button style cut-n-paste plus tabbed shells &
bookmarks (I now can't live without tabbed shells) along with nice
transparent backgrounds for wacky shell eye candy
- NetNewsWire for news aggregator & news reading
- Poisoned for P2P content sharing
- I'm personally hooked on eclipse which the 3.0 M* versions are
great (3.0-M5 is really neat) though IntelliJ is faster on OS X, but
not by that much with recent eclipse builds
- I'm still hooked on OmniOutliner for doing todo lists and stuff; though I like the look of Tinderbox & keep meaning to try moving.
- VoodooPad is cool, a WYSIWYG editor for wiki-ish things; if only it worked natively with moinmoin
- Clutter is just so cool,