I experienced the same yesterday: The blue line got to the end and froze. I was experimenting with 'kismet' to see if I could avoid it screwing the networking, by terminating it with the proper 'Q' key as was adviced in another thread. It didn't, network still wouldn't work afterwards so i rebooted (which fixes the network problem).

Got the problem described above.. stopped at end of blue line and froze (which is different from the boot-up problem I had some weeks ago, where the blue line didn't start - that one was fixed by removing the internal card, which didn't help here), with the NOKIA letters on the white background. Removed the battery, didn't work. Power button didn't work. Tried several times. Then I tried fiddling with _all_ the buttons several times, thinking that there might be something in the bootup that would react if there was any kind of input (this helps on some user-mode linux (UML) boot-up problems). Nothing seemed to happen right away, but I left the unit on the table and suddenly it came up.. all fine after that.

I don't know for certain if touching all the buttons helped, or it was that I left it waiting longer than four or five minutes. I sure wished for a serial line console input while the problem persisted though.. I never liked the fully graphical boot up sequences (my Zaurus actually shows the actual boot up sequence, like my desktop box does.)

Edit: I wonder what caused this to suddenly happen for several people.. I first thought that maybe kismet screwed something up, but it could also be caused by an update that changed some of the stuff that happens during boot-up. 'last' shows the times for reboots. What did you guys update between your last reboot before the problem, and the problematic reboot? I realize that if you actually reflashed you won't have the info readily available.. but for me it seems I had a 'dropbear' update in between (I got another one today though, which may indicate there was some problem with the previous one - I don't know).