Originally Posted by Mark Rejhon

Actually, BlackBerry is getting more and more open source Blackberry -- it's a matter of time before Linux sync is available. Most applications do not even need RIM to sign it. And even so, RIM recently signed open source applications, including BlackChat (to permit it to hook into Notifications; something you don't want a virus to do). Please see the Developer forum for a listing of open source J2ME software; we need more open source developers for BlackBerry!

There's push available for other devices such as Goodlink for TREO. Unfortunately, all of them are more proprietary -- you have to pay a huge arm and leg for these solutions.

If you are a programmer -- why not write your own open source sync software for BlackBerry? The PocketMac people successfully reversed engineer the BlackBerry synchronization, this would help;

Apart from the big $$$$ you have to pay for other push email solutions, don't forget the other BlackBerry advantages:

Longer battery life: Blackberry consistently lasts longer than other handhelds like PalmOS. Example, on the 7280, you can even run instant messenger software for 100 hours nonstop always-on, untethered, with the screen constantly turned on (with backlight turned off).
Ruggedized: Blackberry handhelds survives drops much better than other handhelds such as Treo's or iPaq's
Data Loss Prevention: You can yank the battery out of your BlackBerry for a full week and put it back in one week later, all your data is still there. Everything is written to flash ROM on the fly, even your email drafts, so you don't need to make backups like you would with Palm or iPaq.
Security: All connections are encrypted. And applications need to be signed before they can access critical features interesting to virus authors. Blackberry come with the capability for remote-controlled lobotomy to delete your data if your Blackberry is ever stolen. Blackberry also requires cyptographic signing by RIM before the application can do any damage to the operating system or databases, which makes it much more impossible to write a virus for the BlackBerry than for Palm/PocketPC.
Email Software: The email on the Blackberry is superior to the other wireless push email software, even the recently available Treo push email software;
Stability: Uptimes well over 60 days are getting common on BlackBerry nowadays. Not nearly as common for Palm and iPaq handhelds.
Configuration Free: No need to worry about configuring email software to automatically start up when resetting a Palm; no need to worry about whether the email software is running in the background or if it has crashed. The RIM handheld ensures that email is running at all times; by making it impossible to exit the push email software by accident.
No power button needed:Unlike on Palm/iPaq handhelds, on the Blackberry, it uses so little power, you just put it down -- no need for a power button at all. You can electronically turn off via menus, for those times like airplanes, etc, but with email reception of 4 to 9 days (assuming data-only usage) there is almost no need to turn off the unit. You get email, the email shows up immediately on the screen, and you can put it away immediately without touching a button or screen, if email is not important. No need to click "Do you want to read this message?", the email is automatically displayed pager-style when you pull the BlackBerry out of your holster.

Yes, PalmOS is more flexible but there are over 10 open source applications written recently for the BlackBerry and it is starting to explode; it's still very early, but we are witnessing the head end of an application explosion.

While iPaq/Palm makes better multimedia handhelds (GPS, MAME emulator, 3D videogames, MP3 playback), they don't make very good wireless productivity handhelds.
Instead of looking at inferior "push email" alternatives, I urge you to help us write a Linux synchronization utility for BlackBerry, now that it is technically possible to do so!

My BlackBerry gets 85% usage and my iPaq gets only 15% usage.