I fly regularly and unfortunately the valsalva action described above doesn't work for me. I have had success with moving my jaw previously but not always and I definitely +1 the decongestant suggestion.

The best thing I've found are some earplugs I bought at the airport. I can't remember the brand name, but they're reusable and they came in a pack of 3: 2 adult sets and 1 child set. They're made of silicon and the adult ones are blue and clear and the child ones orange and clear and they have a small cylinder to keep them in that's keychain size.

Edit: I remembered the name - it's Flitemate. Not sure if they're available where you are but if you see something similar they really work for me.

http://www.aant.com.au/AANTShop/View...8/Default.aspx