<p>Is it possible to access the crash log over the application? The last.fm client showed me today a "we found a crash log" altert with the option to send it, so I think it must be possible.</p>

Yes, although you probably won't get much out of them if you don't have the dSYM file and source code:
After you've synced with iTunes the
  crash logs should be in one of the
  following folders:
On Mac OS X they are located in
  ~/Library/Logs/CrashReporter/MobileDevice.
Windows XP: C:\Documents and
  Settings\Application Data\Apple
  computer\Logs\CrashReporter/
Windows Vista:
  C:\Users\AppData\Roaming\Apple
  computer\Logs\CrashReporter/MobileDevice/
(This from the
help page
for my application.)