Would love to join a group to share thoughts and ideas.
I've looked into this before. There is not specifically an arduino or robotics group in Austin. If you get to Dallas once in a while you can drop in on the friendly DPRG.
For Austin, there are some related groups. Dorkbot http://dorkbot.org/dorkbotaustin/
is a "techno-arts" group, more arts than technical. They do some things with arduino.
You might also find some like-minded people at the ATX hackerspace http://atxhackerspace.org/wiki/Main_Page
. They have a "microcontroller mondays" meeting which might include some arduino people.
I haven't had much of a chance lately to get to any of these meetings myself. Let me know how it goes.