What's on my Treo 600

Freeware:

CardTXT v0.35f Text editor which can process files up to 4MB. Very handy for reading TXT books from Project Gutenberg, for example. Here are a few possibilities (for HTML files, just Ctrl+S and choose "Text files" as filetype in Firefox):
Converter 2.2 Unit conversion tool supporting over 200 unit types in 23 different categories.
DefaultDirs v1.0 This application is the easiest way to get rid of "The following file(s) could not be installed to the SecureDigital (SD) Card because there is no application on your handheld to open these files", which is displayed when you try to install a file with an unknown extension onto the SD card. Register, unregister or modify the default directory information for any file extension.
Eudora Internet Suite 2.1 Includes robust email, web browser, and mail conduit. Highly recommended.
HolidayUSA 1.1 Displays the dates for the American holidays for any year later than 1980. Optionally adds all the holidays into the Palm Date Book.
MileageX 1.0 Keep track of car mileage.
Qset 1.0 Adjust JPG compression settings (i.e., take slightly better photos)
Graffiti Anywhere 1.5.7 Use Graffiti anywhere on the Treo's screen. If you prefer Graffiti 1 over Graffiti 2, be sure to check out Graffiti 1 Files for Treo 600.
TuSSH 0.80 SSH 2 client for Palm OS 3.5 and higher

Shareware:

BackupMan 1.53 The best backup app ever for any platform. BackupMan images my entire Treo to SD card every night and archives any number of previous backups. Sort of like Acronis True Image, with two major differences: one, auto delete of backups older than x, and two, a 15 second learning curve. Windows and Mac developers: please copy this idea and contact me when you've got anything close.
PdaNet 3.01 Use the Treo as a wireless modem to connect laptop or desktop PCs to the Internet. Linux and OS X users may want to check out WirelessModem instead.
Phone Technician 1.93 Use MP3, OGG, WAV and MIDI files for ringtone, turn off screen during calls (to save battery power), more.
pTunes 2.3.2 Audio player (received free for registering my Treo online with Palm)
SwitchSync 3.6 While not on the Treo itself, SwitchSync is a Windows app which allows syncing with both Palm Desktop and Microsoft Outlook.
VersaMail 2.7 This was the only modern email client I could find which supported pre-filtering mail before downloading (to avoid wasting time with mail marked *****SPAM*****). Specs and features.

Included Apps:

Contacts & Calendar - I find these more than adequate for my scheduling and contact management needs. If the Treo had nothing more than these 2 apps, I'd still be happy.
Palm Desktop 4.1 - Even if I didn't have a Palm, I'd use this awesome PC-based organizer. Lean, fast, and simple, it's everything Outlook is not.

Hardware:

palmOne Treo 600 Headset This is virtually a mandatory upgrade, as the headset that comes with the Treo is barely audible.
palmOne Treo 600 USB Laptop Travel Cable Just 2 feet long, this USB cable syncs and charges your Treo. UPDATE: While convenient, these cables seem to die fairly quickly - I've gone through several in just over a year.
SimpleTech 256 MB Secure Digital Card Expansion card for storing text files, temple bell ring tone, and nightly automated backups via BackupMan.

Notes:

LCD broken? Replace it
Knowing your various reset options (and the Battery Disconnect method in particular for reviving an ailing battery) can come in handy.
The free Treo Call Log 1.3 for OS X will export your Treo's Call Log to a tab-separated values file.