Travel outbound Nov. 18-24, 2007 and return Nov. 22-24, 2007 or Nov. 27-28, 2007.
For an additional $100 each way, fares are available for:
Travel outbound Dec. 17, 2007 - Jan. 4, 2008 and return Dec. 22, 2007 - Jan. 9, 2008.
Newark to London, for example, is $560 each way over Thanksgiving and $660 each way for travel over the winter holidays, plus tax.
Maybe we're going blind researching all these fares, but we didn't see a last day to purchase listed on Continental's site.