In the future if you have a stuck screen you can try these instructions
(I had to do this myself an hour ago)
Before doing this it's a good idea to make sure your Kindle 2 is completely charged. Even if it is "frozen" it should still charge - that is the charging indicator should light when the charger is connected. If the charging indicator does not light-up check your plug and if that's OK contact Amazon Kindle support.
Once you are satisfied that your Kindle 2 is charged it's time to reset. To do this -
1. Remove your Kindle 2 from the charger.
2. Slide the power switch to the right and hold it there.
3. SLOWLY count to 15 (the switch has to be held in-place for at least 15 seconds).
4. Release the switch.
5. What will happen? At first NOTHING so don't panic.
6. After about 5 to 10 seconds the Kindle 2 will flash on and off several times.
7. The Amazon logo will appear along with a progress bar showing the Kindle is restarting.
8. Next the Home page will load with the ebooks, audio books, and other media you've loaded onto your Kindle.
That's it! You should be back in business ready to read another book.
A few things to remember:
If you only hold the Power button to the right for five to 10 seconds you'll just turn the unit OFF. You have to hold the power button to the right for at least 15 seconds.
If the process above does not work - contact the Amazon Kindle support team. They are very helpful and may be able to do some other trouble-shooting on your device.