Any way to intercept firefox crash on ubuntu?

you could start firefox from a terminal and see whether any messages are generated there

So there is no way to show this terminal window automatically when a crash occured? The problem is that I can not tell people that Ubuntu rocks and force them launch firefox from terminal to explain them the reason why it occasionally crashes.

If apport is enabled and it's really a crash, the report is in /var/crash
A double click will generate information to send and it can be viewed before that.
Logfiles may show e.g. a segfault, in other cases it's most likely related to flash or a faulty addon.
btw.
terminal is an easy, fast and precise way in case to get error messages and what's so complicated about typing in a terminal window: firefox
that's a plus for 'Ubuntu rocks' instead of minus, it takes me in response first before anyone else.
btw. #2
to compare Ubuntu with MS isn't rational since there are different philosophies.

Reference:
https://wiki.ubuntu.com/Apport
https://help.ubuntu.com/community/LinuxLogFiles
https://wiki.ubuntu.com/DebuggingProcedures
http://kb.mozillazine.org/Standard_diagnostic

Breakpad is the bug reporting tool that firefox have included in firefox 3.0 but it is not enabled in ubuntu as firefox would not be able to do anything with it as they do not have the build symbols and because ubuntu prefers you to enter the bug reports in launchpad as the crash may be related to other things than firefox only (compiz, gnome, ...).

see http://forums.mozillazine.org/viewtopic.php?p=3537175#p3537175

As Sam said, apport will normally pop-up automatically when there is a real crash

also the mini-dump produced by breakpad is less informative than a full dump report as reported by apport

  Koen

The problem was that the Apport is disabled on Jaunty by default, so I have to edit /etc/default/apport to enable it. It would worth to mention somewhere that the first step to start troubleshooting is to enable Apport. The information that Apport is disabled on stable systems is hidden on about 5th's page on its description. You usually go to it when you already know that you need Apport to report your bug, but you usually do not have time to read Apport specifications.

 I may miss exact details, but I believe I was confused that the called Apport is not the same as Apport that works as a daemon to intercept crashes. So I though it was enabled. I do not remember correctly, but was there an option (probably during installation) to enable it? Seems like I've checked something like that, but until I manually edited /etc/default/apport, /var/crash was empty.

You're correct, it's confusing for beginners using the 'Report a problem' button and having Apport not enabled. There might be a reason for it, but however, you may file as wishlist to get a feedback.

https://help.ubuntu.com/community/ReportingBugs