I've got a hacked iPhone. I love it. It is by far the best tech gadget I own. Problem is that when I moved to 1.1.2 the phone started crashing all the time after I installed SummerBoard and various other apps. I thought that I was just going to have to live with it. So, after about a month of frustration with using my phone and considering un-hacking it, I finally got it together enough to search the internets for a solution. It turns out that SummerBoard has an option to 'Dim Wallpaper' and that feature is buggy and is the cause of most crashes. I turned it off, rebooted and haven't had a crash again. Yea!
Update: SummerBoard 3.0 final was just released. I just tried turning on this feature again and my phone has been stable. They must have fixed the issue.