I have had the classic green and orange problem. Here's my exact description so you can see if your problem matches up and then you can try what worked for me.
512 shuffle, had it for more than a year, on a G4 mac... all updates all the time... no problems.
One day, blicnking green and orange lights only when plugged into the mac. Still plays the files on the shuffle when disconnected but try to plug it in and nothing. It is not recognized by my mac as an iPod or a drive. Disk utility does not recognize it. It doesn'y mount at all.
OK... my solution, which is an adaptation of a very early post in this thread was to use my PC. The PC recognized that an unknown USB device was inserted but I couldn't do anything with it. I installed iTunes for the first time and then jacked in my iPod. It recognized that an iPod was inserted. I then used Explorer (right click the start menu) to navigate to my ipod and format it (right click on the drive - FORMAT).
Then ejected the ipod and stuck it back in my mac. Ran the updater to restore the iPod. Done.
I can say that I had to plug and unplug it back into my mac (after the PC format) twice as it mounted the first time to my desktop as a drive but iTunes didn't recognize it. iTunes did on the seocnd try.
You should be able to use any PC with iTunes installed... maybe even at the local library or mall if you don't have easy access to one.
Even if you feel you have an identical issue, please start a new thread (after reading through this thread and trying the solutions offered here). If you post a new thread, please let people know the issue and what steps you have taken to try and resolve it.