This is what I have on my 600:
I would go and get BackupMan right now! This application has really saved my butt quite a few times, I would not go a day with out. Works flawlessly and shines when you absolutely need it. Get it at
www.bitsnbolts.com
Snapper Mail, my email client, I love it.
I use File Z, it's okay.
I get lots of mileage for years now from Happy Days, a free program to rememver BDays, etc. Google it as jmjeong and "Happy Days"
Key Caps, helps with the Shift and capitalizing & number typing, etc. Very useful.
SF Cave game to pass the time
Zap2016 game for my 7 year old to play whenever I am talking on my Treo
The rest is for purely professional use.