How to troubleshoot an unstable iPhone/iPod touch:

First of all, rule out a couple of well-known issues:
-the Dim Wallpaper function of SummerBoard often crashes
Solution: turn off this function
-openSSH can be quite unstable on the iPhone 1.1.4
Solution: install Services or an equivalent app and disable SSH except when needed

If none of the above fix your problem, you'll need to figure out the offending application.

Step 1:
Reboot your iPhone/iPod touch.
This is vital, it makes sure no apps are running in the background that dont start when it boots up.

Step 2:
Just play around, flick through the apps that were included with the iPhone/iPod touch just to test it for instabilities.
If your problem occurs, you can rule out any apps that need to be run to start, largely shrinking down your target. Jump to step 5.

Step 3:
Open each application you have installed, one at a time, playing around in between. Once/If your problem occurs, Jump to step 5.

Step 4:
You dont appear to have any problems anymore. Lord knows what was wrong, but rebooting seems to have solved it. Congratulations!

Step 5:
Use whatever program you use to Install/Uninstall apps to remove what you believe to be the problem. If you aren't sure exactly which application it is, uninstall them one at a time until your problem is fixed.

If the program causing the problem is something you need, you can check online, often there is an update to the program, or at least a fix that some other user has figured out. If not, you may need to find an alternative program that performs the same task, or wait for an update to be released, consider contacting the Developers.

Well, I hope this helps users to troubleshoot any problems they may be having with their iPhones/iPod touches